Compact I/O Thermocouple/mV Input Module Catalog Numbers 1769-IT6 User Manual
Important User Information Solid state equipment has operational characteristics differing from those of electromechanical equipment. Safety Guidelines for the Application, Installation and Maintenance of Solid State Controls (publication SGI-1.1 available from your local Rockwell Automation sales office or online at http://www.rockwellautomation.com/literature/) describes some important differences between solid state equipment and hard-wired electromechanical devices.
Summary of Changes We have added an Important statement about the placement of the 1769-IT6 module with regard to the Compact I/O power supplies on page 18. To help you find new and updated information in this release of the manual, we have included change bars as shown to the right of this paragraph.
Summary of Changes Notes: 4 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Table of Contents Preface Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Conventions Used in This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Chapter 1 Overview General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thermocouple/mV Inputs and Ranges .
Table of Contents Field Wiring Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . System Wiring Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terminal Door Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Removing and Replacing the Terminal Block . . . . . . . . . . . . . . . . . . . Wire the Finger-safe Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . Wire the Module .
Table of Contents Channel Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Invalid Channel Configuration Detection . . . . . . . . . . . . . . . . . . . . . . Over-range or Under-range Detection . . . . . . . . . . . . . . . . . . . . . . . . . . Open-circuit Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-critical versus Critical Module Errors . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents Appendix F Configuring I/O Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Configuring Your 1769-IT6 Module with the Generic Profile Configuring a 1769-IT6 Thermocouple Module . . . . . . . . . . . . . . . . . . . 150 for CompactLogix Controllers in RSLogix 5000 Software Appendix G Configuring the 1769-IT6 Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface Read this preface to familiarize yourself with the rest of the manual. Who Should Use This Manual Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use Allen-Bradley Compact I/O and/or compatible controllers, such as MicroLogix 1500 or CompactLogix. Additional Resources These documents contain additional information concerning related Rockwell Automation products.
Preface Notes: 10 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Chapter 1 Overview This chapter describes the 1769-IT6 Thermocouple/mV Input Module and explains how the module reads thermocouple or millivolt analog input data. Included is information about: • the module’s hardware and diagnostic features. • an overview of system and module operation. • compatibility. General Description The thermocouple/mV input module supports thermocouple and millivolt signal measurement.
Chapter 1 Overview Data Formats The data can be configured on board each module as: • engineering units x 1. • engineering units x 10. • scaled-for-PID. • percent of full-scale. • raw/proportional data. Filter Frequencies The module uses a digital filter that provides high frequency noise rejection for the input signals.
Overview Chapter 1 Figure 1 - Hardware Features 8a 1 2a 7a 7a 3 OK OK Thermocouple/mV Thermocouple/mV 5a DANGER Do Not Remove RTB Under Power Unless Area is Non-Hazardous 10a 11 NC CJC 0+ IN 0+ IN 3+ 5b 9 CJC 0IN 0IN 1+ IN 3IN 1- 10 IN 4+ IN 4- 11 IN 2+ IN 2- IN 5+ CJC 1IN 5- 10b CJC 1+ NC Ensure Adjacent Bus Lever is Unlatched/Latched Before/After Removing/Inserting Module 4 6 1769-IT6 2b 7b 7b 8b Item Description 1 Bus lever 2a Upper-panel mounting tab 2b Lower-pane
Chapter 1 Overview General Diagnostic Features The module contains a diagnostic status indicator that helps you identify the source of anomalies that may occur during powerup or during normal channel operation. The status indicator indicates both status and power. Power-up and channel diagnostics are explained in Chapter 5, Diagnostics and Troubleshooting. System Overview The modules communicate to the controller through the bus interface.
Overview Chapter 1 Module Operation When the module receives a differential input from an analog device, the module’s circuitry multiplexes the input into an A/D converter. The converter reads the signal and converts it as required for the type of input. The module also continuously samples the CJC sensors and compensates for temperature changes at the terminal block cold junction, between the thermocouple wire and the input channel.
Chapter 1 Overview Module Field Calibration The module provides autocalibration, which compensates for offset and gain drift of the A/D converter caused by a temperature change within the module. An internal, high-precision, low drift voltage and system ground reference is used for this purpose. The input module performs autocalibration when a channel is initially enabled. In addition, you can program the module to perform a calibration cycle once every 5 minutes.
Chapter 2 Quick Start for Experienced Users Before You Begin This chapter can help you to get started using the 1769-IT6 thermocouple/mV input module. We base the procedures here on the assumption that you have an understanding of Allen-Bradley controllers. You should understand electronic process control and be able to interpret the ladder logic instructions required to generate the electronic signals that control your application.
Chapter 2 Quick Start for Experienced Users Step 1 Be sure that your 1769 system power supply(1) has sufficient current output to support your system configuration. Reference Chapter 3 (Installation and Wiring) (1) The system power supply could be catalog number 1769-PA2, 1769-PB2, 1769-PA4, 1769-PB4, or the internal supply of the MicroLogix 1500 packaged controller. The module’s maximum current draw is: • 100 mA for 5V DC. • 40 mA for 24V DC. Step 2 Attach and lock the module.
Quick Start for Experienced Users Chapter 2 Be sure the bus lever is locked firmly in place. ATTENTION: When attaching I/O modules, it is very important that the bus connectors are securely locked together to be sure of proper electrical connection. 6. Attach an end cap terminator (5) to the last module in the system by using the tongue-and-groove slots as before. 7. Lock the end cap bus terminator (6).
Chapter 2 Quick Start for Experienced Users • To be sure of optimum accuracy, limit overall cable impedance by keeping a cable as short as possible. Locate the module as close to input devices as the application permits. Grounding Guidelines ATTENTION: The possibility exists that a grounded or exposed thermocouple can become shorted to a potential greater than that of the thermocouple itself. Due to possible shock hazard, take care when wiring grounded or exposed thermocouples.
Quick Start for Experienced Users Step 4 Configure the module. Chapter 2 Reference Chapter 4 (Module Data, Status, and Channel Configuration) The configuration file is typically modified by using the programming software compatible with your controller. It can also be modified through the control program, if supported by the controller. See Channel Configuration on page 42 for more information. Step 5 Go through the start-up procedure. Reference Chapter 5 (Diagnostics and Troubleshooting) 1.
Chapter 2 Quick Start for Experienced Users Notes: 22 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Chapter 3 Installation and Wiring This chapter tells you how to: • determine the power requirements for the modules. • avoid electrostatic damage. • install the module. • wire the module’s terminal block. • wire input devices. Compliance to European Union Directives This product is approved for installation within the European Union and EEA regions. It has been designed and tested to meet the following directives.
Chapter 3 Installation and Wiring Power Requirements The module receives power through the bus interface from the 5/24V DC system power supply. The maximum current drawn by the module is: • 100 mA at 5V DC. • 40 mA at 24V DC. General Considerations Compact I/O modules are suitable for use in an industrial environment when installed in accordance with these instructions.
Installation and Wiring Chapter 3 Preventing Electrostatic Discharge ATTENTION: Electrostatic discharge can damage integrated circuits or semiconductors if you touch analog I/O module bus connector pins or the terminal block on the input module. Follow these guidelines when you handle the module: • Touch a grounded object to discharge static potential. • Wear an approved wrist-strap grounding device. • Do not touch the bus connector or connector pins. • Do not touch circuit components inside the module.
Chapter 3 Installation and Wiring Power Supply Distance Compact I/O Compact I/O Compact I/O Compact I/O Compact I/O Compact I/O 1 2 3 4 5 6 7 8 End Cap Compact I/O MicroLogix 1500 Controller with Integrated System Power Supply Compact I/O You can install as many modules as your power supply can support. However, all 1769 I/O modules have a power supply distance ratings.
Installation and Wiring System Assembly Chapter 3 The module can be attached to the controller or an adjacent I/O module before or after mounting. For mounting instructions, see Panel Mounting by Using the Dimensional Template on page 29, or DIN Rail Mounting on page 29. To work with a system that is already mounted, see Replace a Single Module within a System on page 30. Follow this procedure to assemble the Compact I/O system.
Chapter 3 Installation and Wiring 8. Lock the end cap bus terminator (6). IMPORTANT A 1769-ECR or 1769-ECL right or left end cap respectively must be used to terminate the end of the bus. Mounting ATTENTION: During panel or DIN rail mounting of all devices, be sure that all debris (metal chips, wire strands) is kept from falling into the module. Debris that falls into the module could cause damage at powerup.
Installation and Wiring Chapter 3 Panel Mounting by Using the Dimensional Template For more than 2 modules: (number of modules-1) X 35 mm (1,38 in.). Right End Cap Compact I/O Compact I/O Compact I/O 122.6±0.2 (4.826±0.008) Host Controller 132 (5.197) 28.5 (1.12) 35 (1.38) Refer to host controller documentation for this dimension. Important: All dimensions are in mm (inches). Hole spacing tolerance: ±0.04 mm (0.016 in.).
Chapter 3 Installation and Wiring Replace a Single Module within a System The module can be replaced while the system is mounted to a panel (or DIN rail). Follow these steps in order. 1. Remove power. See the important note on page 27. 2. On the module to be removed, remove the upper and lower mounting screws from the module (or open the DIN latches with screwdriver). 3. Move the bus lever to the right to disconnect (unlock) the bus. 4.
Installation and Wiring Chapter 3 • Routing field wiring in a grounded conduit can reduce electrical noise. • If field wiring must cross AC or power cables, be sure that they cross at right angles. • If multiple power supplies are used with analog millivolt inputs, the power supply commons must be connected. Terminal Block Guidelines • Do not use the module’s NC terminals as connection points. • Do not tamper with or remove the CJC sensors on the terminal block.
Chapter 3 Installation and Wiring Noise Prevention Guidelines • To limit the pickup of electrical noise, keep thermocouple and millivolt signal wires as far as possible from power and load lines. • If noise persists for a device, try grounding the opposite end of the cable shield. (You can ground only one end at a time.) Terminal Door Label A removable, write-on label is provided with the module.
Installation and Wiring Chapter 3 Wire the Finger-safe Terminal Block When wiring the terminal block, keep the finger-safe cover in place. 1. Loosen the terminal screws to be wired. 2. Route the wire under the terminal pressure plate. You can use the bare wire or a spade lug. The terminals accept a 6.35 mm (0.25 in.) spade lug. TIP The terminal screws are non-captive. Therefore, it is possible to use a ring lug [maximum 1/4 inch o.d. with a 0.139 inch minimum i.d. (M3.5)] with the module. 3.
Chapter 3 Installation and Wiring Wire the Module ATTENTION: To prevent shock hazard, care should be taken when wiring the module to analog signal sources. Before wiring any module, disconnect power from the system power supply and from any other source to the module. After the module is properly installed, follow the wiring procedure below, using the proper thermocouple extension cable, or Belden 8761 for non-thermocouple applications. Cable Cut foil shield and drain wire.
Installation and Wiring Chapter 3 Figure 3 - Wiring Diagram CJC Sensor NC CJC 0+ + - + IN 0+ Ungrounded Thermocouple Grounded Thermocouple IN 0- CJC 0IN 3+ IN 1 + IN 3- IN 1- Within 10V DC + IN 4+ IN 2+ IN 4- IN 2- IN 5+ - CJC 1- Grounded Thermocouple IN 5CJC 1+ NC CJC Sensor TIP When using an ungrounded thermocouple, the shield must be connected to ground at the module end.
Chapter 3 Installation and Wiring Cold Junction Compensation To obtain accurate readings from each of the channels, the cold junction temperature (temperature at the module’s terminal junction between the thermocouple wire and the input channel) must be compensated for. Two cold junction compensating thermistors have been integrated in the removable terminal block. These thermistors must remain installed to retain accuracy.
Chapter 4 Module Data, Status, and Channel Configuration After installing the 1769-IT6 thermocouple/mV input module, you must configure it for operation, usually by using the programming software compatible with the controller (for example, RSLogix 500 or RSLogix 5000 software). Once configuration is complete and reflected in the ladder logic, you need to operate the module and verify its configuration.
Chapter 4 Module Data, Status, and Channel Configuration Accessing Input Image File Data The input image file represents data words and status words. Input words 0…5 hold the input data that represents the value of the analog inputs for channels 0…5. These data words are valid only when the channel is enabled and there are no errors. Input words 6 and 7 hold the status bits. To receive valid status information, the channel must be enabled.
Module Data, Status, and Channel Configuration Chapter 4 General Status Bits (S0 through S7) Bits S0 through S5 of word 6 contain the general status information for channels 0…5, respectively. Bits S6 and S7 contain general status information for the two CJC sensors (S6 corresponds to CJC0, S7 to CJC1). If set (1), these bits indicate an error (over- or under-range, open-circuit, or input data not valid condition) associated with that channel. The data not valid condition is described below.
Chapter 4 Module Data, Status, and Channel Configuration Over-range Flag Bits (O0 through O7) Over-range bits for channels 0…5 and the CJC sensors are contained in word 7, even-numbered bits. They apply to all input types. When set (1), the over-range flag bit indicates an input signal that is at the maximum of its normal operating range for the represented channel or sensor. The module automatically resets (0) the bit when the data value falls below the maximum for that range.
Module Data, Status, and Channel Configuration Chapter 4 Configuration Data File The default value of the configuration data is represented by zeros in the data file. The structure of the channel configuration file is shown below.
Chapter 4 Module Data, Status, and Channel Configuration Channel Configuration Each channel configuration word consists of bit fields, the settings of which determine how the channel operates. See this table and the descriptions that follow for valid configuration settings and their meanings.
Module Data, Status, and Channel Configuration Chapter 4 Enabling or Disabling a Channel (bit 15) You can enable or disable each of the six channels individually by using bit 15. The module scans enabled channels only. Enabling a channel forces it to be recalibrated before it measures input data. Disabling a channel sets the channel data word to zero. TIP When a channel is not enabled (0), no input is provided to the controller by the A/D converter.
Chapter 4 Module Data, Status, and Channel Configuration TIP The engineering units data formats represent real engineering temperature units provided by the module to the controller. The raw/proportional counts, scaled-for-PID, and percent of full-scale data formats, may yield the highest effective resolutions, but may also require that you convert channel data to real engineering units in your control program.
Module Data, Status, and Channel Configuration Chapter 4 Scaled-for-PID The value presented to the controller is a signed integer, with 0 representing the lower input range and 16,383 representing the upper input range. To obtain the value, the module scales the input signal range to 0…16,383, which is standard to the PID algorithm for the MicroLogix 1500 controller and other Allen-Bradley controllers (for example, SLC controllers).
Chapter 4 Module Data, Status, and Channel Configuration Determining Open-circuit Response (bits 6 and 5) An open-circuit condition occurs when an input device or its extension wire is physically separated or open. This can happen if the wire is cut or disconnected from the terminal block. TIP If either CJC sensor is removed from the module terminal block, its open-circuit bit is set (1) and the module continues to calculate thermocouple readings at reduced accuracy.
Module Data, Status, and Channel Configuration Chapter 4 When selecting a filter frequency, be sure to consider cut-off frequency and channel step response to obtain acceptable noise rejection. Choose a filter frequency so that your fastest-changing signal is below that of the filter’s cut-off frequency. Common Mode Rejection is better than 115 dB at 50 and 60 Hz, with the 50 and 60 Hz filters selected, respectively, or with the 10 Hz filter selected.
Chapter 4 Module Data, Status, and Channel Configuration Channel Cut-off Frequency The filter cut-off frequency, -3 dB, is the point on the frequency response curve where frequency components of the input signal are passed with 3 dB of attenuation. This table shows cut-off frequencies for the supported filters. Table 5 - Filter Frequency versus Channel Cut-off Frequency Filter Frequency Cut-off Frequency 10 Hz 2.62 Hz 50 Hz 13.1 Hz 60 Hz 15.7 Hz 250 Hz 65.
Module Data, Status, and Channel Configuration Chapter 4 Figure 4 - Frequency Response Graphs 10 Hz Input Filter Frequency 50 Hz Input Filter Frequency 0 –3 dB –20 –20 –40 –40 –60 –60 Gain (dB) Gain (dB) 0 –80 -100 -120 –80 -100 -120 -140 -140 -160 -160 -180 -180 - 200 - 200 0 10 30 20 50 40 60 0 Frequency (Hz) 2.
Chapter 4 Module Data, Status, and Channel Configuration Selecting Enable/Disable Cyclic Calibration (word 6, bit 0) Cyclic calibration functions to reduce offset and gain drift errors due to temperature changes within the module. By setting word 6, bit 0 to 0, you can configure the module to perform calibration on all enabled channels. Setting this bit to 1 disables cyclic calibration.
Module Data, Status, and Channel Configuration Chapter 4 Figure 5 - Effective Resolution versus Input Filter Selection for Type B Thermocouples Using 10, 50, and 60 Hz Filters 3.0 Effective Resolution (°C) 2.5 2.0 10 Hz Filter 50 Hz Filter 60 Hz Filter 1.5 1.0 0.5 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Temperature (°C) 5.0 4.5 Effective Resolution (°F) 4.0 3.5 3.0 10 Hz Filter 50 Hz Filter 60 Hz Filter 2.5 2.0 1.5 1.0 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 6 - Effective Resolution versus Input Filter Selection for Type B Thermocouples Using 250, 500, and 1 kHz Filters 200 180 Effective Resolution (°C) 160 140 120 250 Hz Filter 500 Hz Filter 1 kHz Filter 100 80 60 40 20 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Temperature (°C) 350 300 Effective Resolution (°F) 250 250 Hz Filter 500 Hz Filter 1 kHz Filter 200 150 100 50 0 0 500 1000 1500 2000 2500 3000 3500 Temperat
Module Data, Status, and Channel Configuration Chapter 4 Figure 7 - Effective Resolution versus Input Filter Selection for Type C Thermocouples Using 10, 50, and 60 Hz Filters 1.0 0.9 Effective Resolution (°C) 0.8 0.7 0.6 10 Hz 50 Hz 60 Hz 0.5 0.4 0.3 0.2 0.1 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Temperature (°C) 1.8 1.6 Effective Resolution (°F) 1.4 1.2 10 Hz 50 Hz 60 Hz 1.0 0.8 0.6 0.4 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 8 - Effective Resolution versus Input Filter Selection for Type C Thermocouples Using 250, 500, and 1 kHz Filters 90 80 Effective Resolution (°C) 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Temperature (°C) 160 140 Effective Resolution (°F) 120 100 250 Hz 500 Hz 1 kHz 80 60 40 20 0 0 500 1000 1500 2000 2500 3000 3500 4000 Temperature (°F) 54 Rockwell Automation Pu
Module Data, Status, and Channel Configuration Chapter 4 Figure 9 - Effective Resolution versus Input Filter Selection for Type E Thermocouples Using 10, 50, and 60 Hz Filters 4 Effective Resolution (°C) 3 10 Hz 50 Hz 60 Hz 2 1 0 -400 -200 0 200 400 600 800 1000 Temperature (°C) 7 Effective Resolution (°F) 6 5 10 Hz 50 Hz 60 Hz 4 3 2 1 0 -500 0 500 1000 1500 2000 Temperature (°F) Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 55
Chapter 4 Module Data, Status, and Channel Configuration Figure 10 - Effective Resolution versus Input Filter Selection for Type E Thermocouples Using 250, 500, and 1 kHz Filters 90 80 Effective Resolution (°C) 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 -400 -200 0 200 400 600 800 1000 Temperature (°C) 160 140 Effective Resolution (°F) 120 100 250 Hz 500 Hz 1 kHz 80 60 40 20 0 -500 0 500 1000 1500 Temperature (°F) 56 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 200
Module Data, Status, and Channel Configuration Chapter 4 Figure 11 - Effective Resolution versus Input Filter Selection for Type J Thermocouples Using 10, 50, and 60 Hz Filters 0.5 Effective Resolution (°C) 0.4 0.3 10 Hz 50 Hz 60 Hz 0.2 0.1 0 -300 200 700 1200 Temperature (°C) 0.9 0.8 Effective Resolution (°F) 0.7 0.6 10 Hz 50 Hz 60 Hz 0.5 0.4 0.3 0.2 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 12 - Effective Resolution versus Input Filter Selection for Type J Thermocouples Using 250, 500, and 1 kHz Filters 60 Effective Resolution (°C) 50 40 250 Hz 500 Hz 1 kHz 30 20 10 0 -300 200 700 1200 Temperature (°C) 100 90 Effective Resolution (°F) 80 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 -400 0 400 800 1200 1600 2000 Temperature (°F) 58 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Module Data, Status, and Channel Configuration Chapter 4 Figure 13 - Effective Resolution versus Input Filter Selection for Type K Thermocouples Using 10, 50, and 60 Hz Filters 7 6 Effective Resolution (°C) 5 10 Hz 50 Hz 60 Hz 4 3 2 1 0 -400 -200 0 200 400 600 800 1000 1200 1400 Temperature (°C) 14 Effective Resolution (°F) 12 10 10 Hz 50 Hz 60 Hz 8 6 4 2 0 -500 0 500 1000 1500 2000 2500 Temperature (°F) Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 59
Chapter 4 Module Data, Status, and Channel Configuration Figure 14 - Effective Resolution versus Input Filter Selection for Type K Thermocouples Using 250, 500, and 1 kHz Filters 120 Effective Resolution (°C) 100 80 250 Hz 500 Hz 1 kHz 60 40 20 0 -400 -200 0 200 400 600 800 1000 1200 1400 Temperature (°C) 200 180 Effective Resolution (°F) 160 140 120 250 Hz 500 Hz 1 kHz 100 80 60 40 20 0 -500 0 500 1000 1500 2000 Temperature (°F) 60 Rockwell Automation Publication 1769-UM004B-EN
Module Data, Status, and Channel Configuration Chapter 4 Figure 15 - Effective Resolution versus Input Filter Selection for Type N Thermocouples Using 10, 50, and 60 Hz Filters 1.2 Effective Resolution (°C) 1.0 0.8 10 Hz 50 Hz 60 Hz 0.6 0.4 0.2 0 -400 -200 0 200 400 600 800 1000 1200 1400 Temperature (°C) 2.0 1.8 Effective Resolution (°F) 1.6 1.4 1.2 10 Hz 50 Hz 60 Hz 1.0 0.8 0.6 0.4 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 16 - Effective Resolution versus Input Filter Selection for Type N Thermocouples Using 250, 500, and 1 kHz Filters 100 90 80 Effective Resolution (°C) 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 -400 -200 0 200 400 600 800 1000 1200 1400 Temperature (°C) 180 160 Effective Resolution (°F) 140 120 250 Hz 500 Hz 1 kHz 100 80 60 40 20 0 -400 0 400 800 1200 1600 2000 Temperature (°F) 62 Rockwell Automation Publication 1769
Module Data, Status, and Channel Configuration Chapter 4 Figure 17 - Effective Resolution versus Input Filter Selection for Type R Thermocouples Using 10, 50, and 60 Hz Filters 1.6 1.4 Effective Resolution (°C) 1.2 1.0 10 Hz 50 Hz 60 Hz 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 1200 1400 1600 1800 Temperature (°C) 3.0 Effective Resolution (°F) 2.5 2.0 10 Hz 50 Hz 60 Hz 1.5 1.0 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 18 - Effective Resolution versus Input Filter Selection for Type R Thermocouples Using 250, 500, and 1 kHz Filters 120 Effective Resolution (°C) 100 80 250 Hz 500 Hz 1 kHz 60 40 20 0 0 200 400 600 800 1000 1200 1400 1600 1800 Temperature (°C) 200 180 Effective Resolution (°F) 160 140 120 250 Hz 500 Hz 1 kHz 100 80 60 40 20 0 0 500 1000 1500 2000 2500 3000 Temperature (°F) 64 Rockwell Automation Publication 1769-UM0
Module Data, Status, and Channel Configuration Chapter 4 Figure 19 - Effective Resolution versus Input Filter Selection for Type S Thermocouples Using 10, 50, and 60 Hz Filters 1.6 1.4 Effective Resolution (°C) 1.2 1.0 10 Hz 50 Hz 60 Hz 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 1200 1400 1600 1800 Temperature (°C) 3.0 Effective Resolution (°F) 2.5 2.0 10 Hz 50 Hz 60 Hz 1.5 1.0 0.
Chapter 4 Module Data, Status, and Channel Configuration Figure 20 - Effective Resolution versus Input Filter Selection for Type S Thermocouples Using 250, 500, and 1 kHz Filters 120 Effective Resolution (°C) 100 80 250 Hz 500 Hz 1 kHz 60 40 20 0 0 200 400 600 800 1000 1200 1400 1600 1800 Temperature (°C) 200 180 Effective Resolution (°F) 160 140 120 250 Hz 500 Hz 1 kHz 100 80 60 40 20 0 0 500 1000 1500 2000 2500 3000 Temperature (°F) 66 Rockwell Automation Publication 1769-UM0
Module Data, Status, and Channel Configuration Chapter 4 Figure 21 - Effective Resolution versus Input Filter Selection for Type T Thermocouples Using 10, 50, and 60 Hz Filters 5 Effective Resolution (°C) 4 3 10 Hz 50 Hz 60 Hz 2 1 0 -300 -200 -100 0 100 200 300 400 Temperature (°C) 9 8 Effective Resolution (°F) 7 6 10 Hz 50 Hz 60 Hz 5 4 3 2 1 0 -500 -400 -300 -200 -100 0 100 200 300 400 500 600 700 800 Temperature (°F) Rockwell Automation Publication 1769-UM004B-EN-P - March
Chapter 4 Module Data, Status, and Channel Configuration Figure 22 - Effective Resolution versus Input Filter Selection for Type T Thermocouples Using 250, 500, and 1 kHz Filters 80 Effective Resolution (°C) 70 60 50 250 Hz 500 Hz 1 kHz 40 30 20 10 0 -300 -200 -100 0 100 200 300 400 Temperature (°C) 140 Effective Resolution (°F) 120 100 250 Hz 500 Hz 1 kHz 80 60 40 20 0 -500 -400 -300 -200 -100 0 100 200 300 400 500 600 700 800 Temperature (°F) 68 Rockwell Automation Publication 1769-U
Module Data, Status, and Channel Configuration Chapter 4 Table 6 - Effective Resolution versus Input Filter Selection for Millivolt Inputs Filter Frequency ±50 mV ±100 mV 10 Hz 6 µV 6 µV 50 Hz 9 µV 12 µV 60 Hz 9 µV 12 µV 250 Hz 125 µV 150 µV 500 Hz 250 µV 300 µV 1 kHz 1000 µV 1300 µV The table below identifies the number of significant bits used to represent the input data for each available filter frequency.
Chapter 4 Module Data, Status, and Channel Configuration The CJC input is sampled only if one or more channels are enabled for any thermocouple type. The CJC update time is equal to the largest channel update time of any of the enabled thermocouple inputs types. In that case, a single CJC update is done per scan. See the scan diagram on the previous page. The cyclic calibration time applies only when cyclic calibration is enabled and active.
Module Data, Status, and Channel Configuration Chapter 4 If you enable the cyclic autocalibration function, the module update time increases when the autocalibration occurs. To limit its impact on the module update time, the autocalibration function is divided over two module scans. The first part (offset/0) of a channel calibration adds 71 ms and the second part (gain/span) adds 112 ms to the module update. This takes place over two consecutive module scans.
Chapter 4 Module Data, Status, and Channel Configuration EXAMPLE 72 3. Three Channels Enabled for Different Inputs with Cyclic Calibration Enabled Channel 0 Input: Type T Thermocouple with 60 Hz Filter Channel 1 Input: Type T Thermocouple with 60 Hz Filter Channel 2 Input: Type J Thermocouple with 60 Hz Filter From Channel Update Time, on page 42.
Module Data, Status, and Channel Configuration Chapter 4 Impact of Autocalibration on Module Startup During Mode Change Regardless of the selection of the Enable/Disable Cyclic Calibration function, an autocalibration cycle occurs automatically on a mode change from Program-to-Run and on subsequent module startups/initialization for all configured channels.
Chapter 4 Module Data, Status, and Channel Configuration Notes: 74 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Chapter 5 Diagnostics and Troubleshooting This chapter describes troubleshooting the thermocouple/mV input module. This chapter contains information on: • safety considerations while troubleshooting. • internal diagnostics during module operation. • module errors. • contacting Rockwell Automation for technical assistance. Safety Considerations Safety considerations are an important element of proper troubleshooting procedures.
Chapter 5 Diagnostics and Troubleshooting Program Alteration There are several possible causes of alteration to the user program, including extreme environmental conditions, Electromagnetic Interference (EMI), improper grounding, improper wiring connections, and unauthorized tampering. If you suspect a program has been altered, check it against a previously saved master program.
Diagnostics and Troubleshooting Channel Diagnostics Chapter 5 When an input channel is enabled, the module performs a diagnostic check to see that the channel has been properly configured. In addition, the channel is tested on every scan for configuration errors, over-range and under-range, and open-circuit conditions. Invalid Channel Configuration Detection Whenever a channel configuration word is improperly defined, the module reports an error.
Chapter 5 Diagnostics and Troubleshooting Non-critical versus Critical Module Errors Non-critical module errors are typically recoverable. Channel errors (over-range or under-range errors) are non-critical. Non-critical error conditions are indicated in the module input data table. Critical module errors are conditions that may prevent normal or recoverable operation of the system.
Diagnostics and Troubleshooting Chapter 5 Extended-error Information Field Check the extended error information field when a non-zero value is present in the module error field. Depending upon the value in the module error field, the extended error information field can contain error codes that are module-specific or common to all 1769 analog modules. TIP If no errors are present in the module error field, the extended error information field is set to zero.
Chapter 5 Diagnostics and Troubleshooting Error Codes This table explains the extended error code.
Diagnostics and Troubleshooting Chapter 5 Table 11 - Extended Error Codes Error Type Module-specific configuration error Hex Equivalent(1) Module Error Code Extended Error Information Code Error Description Binary Binary X400 010 0 0000 0000 General configuration error; no additional information X401 010 0 0000 0001 Invalid input type selected (channel 0) X402 010 0 0000 0010 Invalid input type selected (channel 1) X403 010 0 0000 0011 Invalid input type selected (channel 2) X404
Chapter 5 Diagnostics and Troubleshooting Module Inhibit Function Some controllers support the module inhibit function. See your controller manual for details. Whenever the 1769-IT6 module is inhibited, the module continues to provide information about changes at its inputs to the 1769 CompactBus master (for example, a CompactLogix controller).
Appendix A Specifications Table 12 - General Specifications - 1769-IT6 Attribute 1769-IT6 Dimensions (HxDxW), approx. 118 x 87 x 35 mm (4.65 x 3.43 x 1.38 in.) height including mounting tabs is 138 mm (5.43 in.) Shipping weight (with carton), approx. 276 g (0.61 lb) Storage temperature -40…85 °C (-40…185 °F) Operating temperature 0…60 °C (32…140 °F) Operating humidity 5…95% noncondensing Operating altitude 2000 m (6561 ft) Vibration, operating 10…500 Hz, 5 g, 0.030 in.
Appendix A Specifications Table 12 - General Specifications - 1769-IT6 Attribute 1769-IT6 Electrical /EMC The module has passed testing at the following levels. ESD immunity (IEC61000-4-2) 4 kV contact, 8 kV air, 4 kV indirect Radiated immunity (IEC61000-4-3) 10 V/m , 80…1000 MHz, 80% amplitude modulation, 900 MHz keyed carrier Fast transient burst (IEC61000-4-4) 2 kV, 5 kHz Surge immunity (IEC61000-4-5) 1kV galvanic gun Conducted immunity (IEC61000-4-6) 10V, 0.
Specifications Appendix A Table 13 - Input Specifications - 1769-IT6 Attribute 1769-IT6 Module OK status indicator On: module has power, has passed internal diagnostics, and is communicating over the bus. Off: Any of the above is not true. Channel diagnostics Over- or under-range and open-circuit by bit reporting Vendor I.D.
Appendix A Specifications Table 15 - Accuracy With Autocalibration Enabled Input Type(1) (2) (3) Accuracy Filters, max for 10 Hz, 50 Hz, and 60 Hz Without Autocalibration Temperature Drift, max(2) (4) At 25 °C (77 °F) Ambient At 0…60 °C (32…140 °F) Ambient At 0…60 °C (32…140 °F) Ambient Thermocouple J (-210…1200 °C (-346…2192 °F)) ±0.6 °C (± 1.1 °F) ±0.9 °C (± 1.7 °F) ±0.0218 °C/°C (±0.0218 °F/°F) Thermocouple N (-200…1300 °C (-328…2372 °F)) ±1 °C (± 1.8 °F) ±1.5 °C (±2.7 °F) ±0.
Specifications Appendix A Accuracy versus Thermocouple Temperature and Filter Frequency The following graphs show the module’s accuracy when operating at 25 °C (77 °F) for each thermocouple type over the thermocouple’s temperature range for each frequency. The effect of errors in cold junction compensation is not included. Figure 23 - Module Accuracy at 25 °C (77 °F) Ambient for Type B Thermocouple Using 10, 50, and 60 Hz Filter 3.0 2.5 Accuracy °C 2.0 10 Hz 50 Hz 60 Hz 1.5 1.0 0.
Appendix A Specifications Figure 24 - Module Accuracy at 25 °C (77 °F) Ambient for Type B Thermocouple Using 250, 500, and 1 kHz Filter 100 90 80 Accuracy °C 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 0 200 400 600 800 1000 1200 1400 Thermocouple Temperature °C 1600 1800 2000 200 180 160 Accuracy °F 140 120 250 Hz 500 Hz 1 kHz 100 80 60 40 20 0 500 88 1000 1500 2000 2500 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 3000 3500
Specifications Appendix A Figure 25 - Module Accuracy at 25 °C (77 °F) Ambient for Type C Thermocouple Using 10, 50, and 60 Hz Filter 2.0 1.8 1.6 1.4 Accuracy °C 1.2 10 Hz 50 Hz 60 Hz 1.0 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Thermocouple Temperature °C 3.5 3 Accuracy °F 2.5 10 Hz 50 Hz 60 Hz 2 1.5 1 0.
Appendix A Specifications Figure 26 - Module Accuracy at 25 °C (77 °F) Ambient for Type C Thermocouple Using 250, 500, and 1 kHz Filter 45 40 35 30 250 Hz 500 Hz 1 kHz Accuracy °C 25 20 15 10 5 0 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Thermocouple Temperature °C 80 70 Accuracy °F 60 50 250 Hz 500 Hz 1 kHz 40 30 20 10 0 0 500 1000 1500 2000 2500 3000 Thermocouple Temperature °F 90 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 3500 4000 4500
Specifications Appendix A Figure 27 - Module Accuracy at 25 °C (77 °F) Ambient for Type E Thermocouple Using 10, 50, and 60 Hz Filter 4.5 4.0 3.5 Accuracy °C 3.0 10 Hz 50 Hz 60 Hz 2.5 2.0 1.5 1.0 0.
Appendix A Specifications Figure 28 - Module Accuracy at 25 °C (77 °F) Ambient for Type E Thermocouple Using 250, 500, and 1 kHz Filter 60 50 Accuracy °C 40 250 Hz 500 Hz 1 kHz 30 20 10 0 -400 -200 0 200 400 600 Thermocouple Temperature °C 800 1000 100 90 80 Accuracy °F 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 -500 92 0 500 1000 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 1500 2000
Specifications Appendix A Figure 29 - Module Accuracy at 25 °C (77 °F) Ambient for Type J Thermocouple Using 10, 50, and 60 Hz Filter 0.6 Accuracy °C 0.5 0.4 10 Hz 50 Hz 60 Hz 0.3 0.2 0.1 0 -400 -200 0 200 400 600 Thermocouple Temperature °C 800 1000 1200 1.0 0.9 0.8 Accuracy °F 0.7 0.6 10 Hz 50 Hz 60 Hz 0.5 0.4 0.3 0.2 0.
Appendix A Specifications Figure 30 - Module Accuracy at 25 °C (77 °F) Ambient for Type J Thermocouple Using 250, 500, and 1 kHz Filter 30 25 Accuracy °C 20 250 Hz 500 Hz 1 kHz 15 10 5 0 -400 -200 0 200 400 600 Thermocouple Temperature °C 800 1000 1200 60 50 Accuracy °F 40 250 Hz 500 Hz 1 kHz 30 20 10 0 -400 94 0 400 800 1200 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 1600 2000
Specifications Appendix A Figure 31 - Module Accuracy at 25 °C (77 °F) Ambient for Type K Thermocouple Using 10, 50, and 60 Hz Filter 8 7 Accuracy °C 6 5 10 Hz 50 Hz 60 Hz 4 3 2 1 0 -400 -200 0 200 400 600 800 1000 1200 1400 Thermocouple Temperature °C 14 12 Accuracy °F 10 8 10 Hz 50 Hz 60 Hz 6 4 2 0 -500 0 500 1000 1500 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 2000 2500 95
Appendix A Specifications Figure 32 - Module Accuracy at 25 °C (77 °F) Ambient for Type K Thermocouple Using 250, 500, and 1 kHz Filter 80 70 Accuracy °C 60 50 250 Hz 500 Hz 1 kHz 40 30 20 10 0 -400 -200 0 200 400 600 800 1000 1200 1400 Thermocouple Temperature °C 140 120 Accuracy °F 100 250 Hz 500 Hz 1 kHz 80 60 40 20 0 -500 96 0 500 1000 1500 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 2000 2500
Specifications Appendix A Figure 33 - Module Accuracy at 25 °C (77 °F) Ambient for Type N Thermocouple Using 10, 50, and 60 Hz Filter 1.2 1.0 Accuracy °C 0.8 10 Hz 50 Hz 60 Hz 0.6 0.4 0.2 0 -400 -200 0 200 400 600 800 Thermocouple Temperature °C 1000 1200 1400 2.2 2.0 1.8 Accuracy °F 1.6 1.4 10 Hz 50 Hz 60 Hz 1.2 1.0 0.8 0.6 0.4 0.
Appendix A Specifications Figure 34 - Module Accuracy at 25 °C (77 °F) Ambient for Type N Thermocouple Using 250, 500, and 1 kHz Filter 60 50 Accuracy °C 40 250 Hz 500 Hz 1 kHz 30 20 10 0 -400 -200 0 200 400 600 800 Thermocouple Temperature °C 1000 1200 1400 100 90 80 Accuracy °F 70 60 250 Hz 500 Hz 1 kHz 50 40 30 20 10 0 -400 98 0 400 800 1200 1600 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 2000 2400
Specifications Appendix A Figure 35 - Module Accuracy at 25 °C (77 °F) Ambient for Type R Thermocouple Using 10, 50, and 60 Hz Filter 1.8 1.6 1.4 Accuracy °C 1.2 10 Hz 50 Hz 60 Hz 1.0 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 1200 Thermocouple Temperature °C 1400 1600 1800 3.5 3 Accuracy °F 2.5 10 Hz 50 Hz 60 Hz 2 1.5 1 0.
Appendix A Specifications Figure 36 - Module Accuracy at 25 °C (77 °F) Ambient for Type R Thermocouple Using 250, 500, and 1 kHz Filter 60 50 Accuracy °C 40 250 Hz 500 Hz 1 kHz 30 20 10 0 0 200 400 600 800 1000 1200 Thermocouple Temperature °C 1400 1600 1800 120 100 Accuracy °F 80 250 Hz 500 Hz 1 kHz 60 40 20 0 0 100 500 1000 1500 2000 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 2500 3000
Specifications Appendix A Figure 37 - Module Accuracy at 25 °C (77 °F) Ambient for Type S Thermocouple Using 10, 50, and 60 Hz Filter 1.8 1.6 1.4 Accuracy °C 1.2 10 Hz 50 Hz 60 Hz 1.0 0.8 0.6 0.4 0.2 0 0 200 400 600 800 1000 1200 Thermocouple Temperature °C 1400 1600 1800 3.0 2.5 Accuracy °F 2.0 10 Hz 50 Hz 60 Hz 1.5 1.0 0.
Appendix A Specifications Figure 38 - Module Accuracy at 25 °C (77 °F) Ambient for Type S Thermocouple Using 250, 500, and 1 kHz Filter 60 50 Accuracy °C 40 250 Hz 500 Hz 1 kHz 30 20 10 0 0 200 400 600 800 1000 1200 Thermocouple Temperature °C 1400 1600 1800 120 100 Accuracy °F 80 250 Hz 500 Hz 1 kHz 60 40 20 0 0 102 500 1000 1500 2000 Thermocouple Temperature °F 2500 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 3000
Specifications Appendix A Figure 39 - Module Accuracy at 25 °C (77 °F) Ambient for Type T Thermocouple Using 10, 50, and 60 Hz Filter 6 5 Accuracy °C 4 10 Hz 50 Hz 60 Hz 3 2 1 0 -300 -200 -100 0 100 200 Thermocouple Temperature °C 300 400 10 9 8 Accuracy °F 7 6 5 4 10 Hz 50 Hz 60 Hz 3 2 1 0 -500 -400 -300 -200 -100 0 100 200 300 400 500 600 700 800 Thermocouple Temperature °F Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 103
Appendix A Specifications Figure 40 - Module Accuracy at 25 °C (77 °F) Ambient for Type T Thermocouple Using 250, 500, and 1 kHz Filter 50 45 40 Accuracy °C 35 30 250 Hz 500 Hz 1 kHz 25 20 15 10 5 0 -300 -200 -100 0 100 200 300 400 Thermocouple Temperature °C 50 45 40 Accuracy °F 35 30 250 Hz 500 Hz 1 kHz 25 20 15 10 5 0 -500 -400 -300 -200 -100 0 100 200 300 400 500 600 700 800 Thermocouple Temperature °F 104 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Specifications Temperature Drift Appendix A The graphs below show the module’s temperature drift without autocalibration for each thermocouple type over the thermocouple’s temperature range, assuming terminal block temperature is stable. The effects of CJC temperature drift are not included. Figure 41 - Module Temperature Drift Using Type B Thermocouple 0.12 Temperature Drift °C/°C 0.10 0.08 0.06 0.04 0.
Appendix A Specifications Figure 43 - Module Temperature Drift Using Type E Thermocouple 0.30 Temperature Drift °C/°C 0.25 0.20 0.15 0.10 0.05 0 -400 -200 0 200 400 Thermocouple Temperature °C 600 800 1000 Figure 44 - Module Temperature Drift Using Type J Thermocouple 0.025 Temperature Drift °C/°C 0.020 0.015 0.010 0.
Specifications Appendix A Figure 45 - Module Temperature Drift Using Type K Thermocouple 0.5 Temperature Drift °C/°C 0.4 0.3 0.2 0.1 0 -400 -200 0 200 400 600 800 Thermocouple Temperature °C 1000 1200 1400 1200 1400 Figure 46 - Module Temperature Drift Using Type N Thermocouple 0.05 Temperature Drift °C/°C 0.04 0.03 0.02 0.
Appendix A Specifications Figure 47 - Module Temperature Drift Using Type R Thermocouple 0.07 Temperature Drift °C/°C 0.06 0.05 0.04 0.03 0.02 0.01 0 0 200 400 600 800 1000 1200 Thermocouple Temperature °C 1400 1600 1800 1600 1800 Figure 48 - Module Temperature Drift Using Type S Thermocouple 0.07 Temperature Drift °C/°C 0.06 0.05 0.04 0.03 0.02 0.
Specifications Appendix A Figure 49 - Module Temperature Drift Using Type T Thermocouple 0.4 Temperature Drift °C/°C 0.3 0.2 0.
Appendix A Specifications Notes: 110 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Appendix B Two’s Complement Binary Numbers The processor memory stores 16-bit binary numbers. Two’s complement binary is used when performing mathematical calculations internal to the processor. Analog input values from the analog modules are returned to the processor in 16-bit two’s complement binary format. For positive numbers, the binary notation and two’s complement binary notation are identical.
Appendix B Two’s Complement Binary Numbers Negative Decimal Values In two’s complement notation, the leftmost position is always 1 for negative values. The equivalent decimal value of the binary number is obtained by subtracting the value of the leftmost position, 32,768, from the sum of the values of the other positions. In the figure below (all positions are 1), the value is 32,767 - 32,768 = -1. This is an example.
Appendix C Thermocouple Descriptions The information in this appendix was extracted from the NIST Monograph 175 issued in January 1990, which supersedes the IPTS-68 Monograph 125 issued in March 1974. NIST Monograph 175 is provided by the United States Department of Commerce, National Institute of Standards and Technology.
Appendix C Thermocouple Descriptions Studies by Ehringer [39], Walker et al. [25,26], and Glawe and Szaniszlo [24] have demonstrated that thermocouples, in which both legs are platinum-rhodium alloys, are suitable for reliable temperature measurements at high temperatures. Such thermocouples have been shown to offer the following distinct advantages over types R and S thermocouples at high temperatures: (1) improved stability, (2) increased mechanical strength, and (3) higher operating temperatures.
Thermocouple Descriptions Appendix C The suggested upper temperature limit of 1700 °C (3092 °F) given in the ASTM standard [7] for protected type B thermocouples applies to 0.51 mm2 (24 AWG) wire. This temperature limit applies to thermocouples used in conventional closed-end protecting tubes and it is intended only as a rough guide to the user. It does not apply to thermocouples having compacted mineral oxide insulation.
Appendix C Thermocouple Descriptions They also should not be used in vacuum (at high temperatures) for extended times because the chromium in the positive thermoelement, a nickel-chromium alloy, vaporizes out of solution and alters the calibration. In addition, their use in atmospheres that promote ‘green-rot’ corrosion of the positive thermoelement should be avoided.
Thermocouple Descriptions Appendix C The suggested upper temperature limit, 870 °C (1598 °F), given in the ASTM standard [7] for protected type E thermocouples applies to 3.25 mm2 (8 AWG) wire. It decreases to 650 °C (1202 °F) for 1.63 mm2 (14 AWG), 540 °C (1004 °F) for 0.81 mm2 (20 AWG), 430 °C (806 °F) for 0.51 or 0.33 mm2 (24 or 28 AWG), and 370 °C (698 °F) for 0.25 mm2 (30 AWG).
Appendix C Thermocouple Descriptions Type J thermocouples are recommended by the ASTM [5] for use in the temperature range from 0…760 °C (32…1400 °F) in vacuum, oxidizing, reducing, or inert atmospheres. If used for extended times in air above 500 °C (932 °F), heavy gauge wires are recommended because the oxidation rate is rapid at elevated temperatures. Oxidation normally causes a gradual decrease in the thermoelectric voltage of the thermocouple with time.
Thermocouple Descriptions Type K Thermocouples Appendix C This section describes nickel-chromium alloy versus nickel-aluminum alloy thermocouples, called type K thermocouples. This type is more resistant to oxidation at elevated temperatures than types E, J, or T thermocouples and, consequently, it finds wide application at temperatures above 500 °C (932 °F). The positive thermoelement, KP, which is the same as EP, is an alloy that typically contains about 89 or 90% nickel, 9 or 9.
Appendix C Thermocouple Descriptions In addition, avoid their use in atmospheres that promote ‘green-rot’ corrosion [9] of the positive thermoelement. Such corrosion results from the preferential oxidation of chromium in atmospheres with low, but not negligible, oxygen content and can lead to a large decrease in the thermoelectric voltage of the thermocouple with time. The effect is most serious at temperatures between 800 °C (1472 °F) and 1050 °C (1922 °F).
Thermocouple Descriptions Type N Thermocouples Appendix C This section describes nickel-chromium-silicon alloy versus nickel-silicon-magnesium alloy thermocouples, commonly referred to as type N thermocouples. This type is the newest of the letter-designated thermocouples. It offers higher thermoelectric stability in air above 1000 °C (1832 °F) and better air-oxidation resistance than types E, J, and K thermocouples.
Appendix C Thermocouple Descriptions In addition, their use in atmospheres with low, but not negligible, oxygen content is not recommended, because it can lead to changes in calibration due to the preferential oxidation of chromium in the positive thermoelement.
Thermocouple Descriptions Appendix C The suggested upper temperature limit of 1260 °C (2300 °F) given in the ASTM standard [7] for protected type N thermocouples applies to 3.25 mm2 (8 AWG) wire. It decreases to 1090 °C (1994 °F) for 1.63 mm2 (14 AWG), 980 °C (1796 °F) for 0.81 mm2 (20 AWG), 870 °C (1598 °F) for 0.51 or 33 mm2 (24 or 28 AWG), and 760 °C (1400 °F) for 0.25 mm2 (30 AWG).
Appendix C Thermocouple Descriptions ASTM Standard E230-87 in the 1992 Annual Book of ASTM Standards [7] specifies that the initial calibration tolerances for type R commercial thermocouples be ±1.5 °C (±34.7 °F) or ±0.25% (whichever is greater) between 0 °C (32 °F) and 1450 °C (2642 °F). Type R thermocouples can be supplied to meet special tolerances of ±0.6 °C (±33.08 °F) or ±0.1% (whichever is greater).
Thermocouple Descriptions Appendix C Research [27] demonstrated that type S thermocouples can be used from -50 °C (-58 °F) to the platinum melting-point temperature. They may be used intermittently at temperatures up to the platinum melting point and continuously up to about 1300 °C (2372 °F) with only small changes in their calibrations.
Appendix C Thermocouple Descriptions The positive thermoelement is unstable in a thermal neutron flux because the rhodium converts to palladium. The negative thermoelement is relatively stable to neutron transmutation. Fast neutron bombardment, however, will cause physical damage, which will change the thermoelectric voltage unless it is annealed out. At the gold freezing-point temperature, 1064.18 °C (1947.
Thermocouple Descriptions Appendix C The negative thermoelement, TN or EN, is a copper-nickel alloy known ambiguously as constantan. The word constantan refers to a family of copper-nickel alloys containing anywhere from 45…60% copper. These alloys also typically contain small percentages of cobalt, manganese and iron, as well as trace impurities of other elements such as carbon, magnesium, silicon, and so forth.
Appendix C Thermocouple Descriptions At this temperature the type TN thermoelements have good resistance to oxidation and exhibit only small voltage changes heated in air for long periods of time, as shown by the studies of Dahl [11]. Higher operating temperatures, up to at least 800 °C (1472 °F), are possible in inert atmospheres where the deterioration of the type TP thermoelement is no longer an anomaly.
Thermocouple Descriptions References Appendix C [1] Preston-Thomas, H. The International Temperature Scale of 1990 (ITS-90). Metrologia 27, 3-10; 1990. ibid. p. 107. [2] The International Practical Temperature Scale of 1968, Amended Edition of 1975. Metrologia 12, 7-17, 1976. [3] Mangum, B. W.; Furukawa, G. T. Guidelines for realizing the International Temperature Scale of 1990 (ITS-90). Natl. Inst. Stand. Technol. Tech. Note 1265; 1990 August. 190 p. [4] The 1976 Provisional 0.
Appendix C Thermocouple Descriptions [14] Potts, J. F. Jr.; McElroy, D. L. The effects of cold working, heat treatment, and oxidation on the thermal emf of nickel-base thermoelements. Herzfeld, C. M.; Brickwedde, F. G.; Dahl, A. I.; Hardy, J. D., ed. Temperature: Its Measurement and Control in Science and Industry; Vol. 3, Part 2; New York: Reinhold Publishing Corp.; 1962. 243-264. [15] Burley, N. A.; Ackland, R. G. The stability of the thermo-emf/temperature characteristics of nickel-base thermocouples.
Thermocouple Descriptions Appendix C [24] Glawe, G. E.; Szaniszlo, A. J. Long-term drift of some noble- and refractory-metal thermocouples at 1600K in air, argon, and vacuum. Temperature: Its Measurement and Control in Science and Industry; Vol. 4; Plumb, H. H., ed.; Pittsburgh: Instrument Society of America; 1972. 1645-1662. [25] Walker, B. E.; Ewing, C. T.; Miller, R. R. Thermoelectric instability of some noble metal thermocouples at high temperatures. Rev. Sci. Instrum. 33, 1029-1040; 1962.
Appendix C Thermocouple Descriptions [33] McLaren, E. H.; Murdock, E. G. Properties of some noble and base metal thermocouples at fixed points in the range 0-1100°C. Temperature: Its Measurement and Control in Science and Industry; Vol. 5; Schooley, J. F., ed.; New York: American Institute of Physics; 1982. 953-975. [34] Bentley, R. E.; Jones, T. P. Inhomogeneities in type S thermocouples when used to 1064°C. High Temperatures- High Pressures 12, 33-45; 1980. [35] Rhys, D. W.; Taimsalu, P.
Thermocouple Descriptions Appendix C [46] Burley, N. A.; Hess, R. M.; Howie, C. F. Nicrosil and nisil: new nickel-based thermocouple alloys of ultra-high thermoelectric stability. High Temperatures- High Pressures 12, 403-410; 1980. [47] Burley, N. A.; Cocking, J. L.; Burns, G. W.; Scroger, M. G. The nicrosil versus nisil thermocouple: the influence of magnesium on the thermoelectric stability and oxidation resistance of the alloys. Temperature: Its Measurement and Control in Science and Industry; Vol.
Appendix C Thermocouple Descriptions [57] Bentley, R. E. The new nicrosil-sheathed type N MIMS thermocouple: an assessment of the first production batch. Mater. Australas. 18(6), 16-18; 1986. [58] Bentley, R. E.; Russell, Nicrosil sheathed mineral-insulated type N thermocouple probes for short-term variable-immersion applications to 1100°C. Sensors and Actuators 16, 89-100; 1989. [59] Bentley, R. E.
Appendix D Using Thermocouple Junctions This appendix describes the types of thermocouple junctions available, and explains the trade-offs in using them with the 1769-IT6 thermocouple/mV analog input module. ATTENTION: Take care when choosing a thermocouple junction, and connecting it from the environment to the module. If you do not take adequate precautions for a given thermocouple type, the electrical isolation of the module might be compromised. Available thermocouple junctions are: • grounded.
Appendix D Using Thermocouple Junctions The shield input terminals for a grounded junction thermocouple are connected together and then connected to chassis ground. Use of this thermocouple with an electrically conductive sheath removes the thermocouple signal to chassis ground isolation of the module. In addition, if multiple grounded junction thermocouples are used, the module channel-to-channel isolation is removed, because there is no isolation between signal and sheath (sheaths are tied together).
Using Thermocouple Junctions Using an Ungrounded (isolated) Junction Thermocouple Appendix D An ungrounded (isolated) junction thermocouple uses a measuring junction that is electrically isolated from the protective metal sheath. This junction type is often used in situations when noise will affect readings, as well as situations using frequent or rapid temperature cycling. For this type of thermocouple junction, the response time is longer than for the grounded junction.
Appendix D Using Thermocouple Junctions As shown in the next illustration, using an exposed junction thermocouple can result in removal of channel-to-channel isolation. Isolation is removed if multiple exposed thermocouples are in direct contact with electrically conductive process material.
Appendix E Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software This appendix examines the 1769-IT6 module’s addressing scheme and describes module configuration by using RSLogix 500 and a MicroLogix 1500 controller. Module Addressing This memory map shows the input and configuration image tables for the module. For detailed information on the image table, see Chapter 4.
Appendix E Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software For example, to obtain the general status of channel 2 of the module located in slot e, use address I:e.6/2. Figure 56 - General Status of Channel 2 Slot Word Bit I:e.6/2 Input File Type Compact I/O Compact I/O Compact I/O 0 1 2 3 End Cap Adapter Element Delimiter Word Delimiter Bit Delimiter Slot Number TIP The end cap does not use a slot address.
Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software Configuring the 1769-IT6 Module in a MicroLogix 1500 System Appendix E This example takes you through configuring your 1769-IT6 thermocouple/mV input module with RSLogix 500 programming software, assumes your module is installed as expansion I/O in a MicroLogix 1500 system, and that RSLinx software is properly configured and a communication link has been established between the MicroLogix processor and RSLogix 500 software.
Appendix E Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software A communication dialog box appears, identifying the current communication configuration so that you can verify the target controller. If the communication settings are correct, click Read IO Config. The actual I/O configuration is displayed. In this example, a second tier of I/O is attached to the MicroLogix 1500 processor.
Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software Appendix E The 1769-IT6 module is installed in slot 1. To configure the module, double-click the module/slot. The general configuration dialog box appears. Configuration options for channels 0…2 are on a separate tab from channels 3…5, as shown below. To enable a channel, click its Enable box so that a checkmark appears. For optimum module performance, disable any channel that is not hardwired to a real input.
Appendix E Module Configuration by Using a MicroLogix 1500 System and RSLogix 500 Software Configuring Cyclic Calibration The Cal tab contains a checkbox for disabling cyclic calibration. See Selecting Enable/Disable Cyclic Calibration (word 6, bit 0) on page 50 for more information. Generic Extra Data Configuration This tab redisplays the configuration information entered on the Analog Input Configuration screen in a raw data format.
Appendix F Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software The procedure in this example is used only when your 1769-IT6 thermocouple module profile is not available in RSLogix 5000 Programming Software. The initial release of the CompactLogix5320 controller includes the 1769 Generic I/O Profile, with individual 1769 I/O module profiles to follow.
Appendix F Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software Choose your controller type and enter a name for your project, then click OK. This main RSLogix 5000 dialog box appears. In the Controller Organizer on the left of the dialog box, right-click ‘[0] CompactBus Local’, choose New Module. This dialog box appears. Use this dialog box to narrow your search for I/O modules to configure into your system.
Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software Appendix F Click OK and this default Generic Profile dialog box appears. First, choose the Comm Format (‘Input Data – INT’ for the 1769-IT6 module), then fill in the name field. For this example, ‘IT6’ is used to help identify the module type in the Controller Organizer. The Description field is optional and may be used to provide more details concerning this I/O module in your application.
Appendix F Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software When complete, the Generic Profile for a 1769-IT6 module should look like this. At this point, you may click ‘Finish’ to complete the configuration of your I/O module. Configure each I/O module in this manner. The CompactLogix5320 controller supports a maximum of eight I/O modules. The valid slot numbers to select when configuring I/O modules are 1…8.
Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software Appendix F Based on the Generic Profile created earlier for 1769- IT6 module, the Controller Tags dialog box looks like this. Tag addresses are automatically created for configured I/O modules. All local I/O addresses are preceded by the word Local.
Appendix F Configuring Your 1769-IT6 Module with the Generic Profile for CompactLogix Controllers in RSLogix 5000 Software Configuring a 1769-IT6 Thermocouple Module To configure the 1769-IT6 module in slot 1, click the plus sign left of Local:1:C. Configuration data is entered under the Local:1:C.Data tag. Click the plus sign to the left of Local:1:C.Data to reveal the eight integer data words where configuration data may be entered for the 1769-IT6 module.
Appendix G Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter This application example assumes your 1769-IT6 thermocouple input module is in a remote DeviceNet system controlled by a 1769-ADN DeviceNet adapter. RSNetworx for DeviceNet software is not only used to configure your DeviceNet network, but is also used to configure individual I/O modules in remote DeviceNet adapter systems.
Appendix G Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter Start RSNetWorx for DeviceNet software. This dialog box appears. In the left column under Category, click the ‘+’ sign next to Communication Adapters. The list of products under Communication Adapters contains the 1769-ADN/A adapter. Should this adapter not appear under Communication Adapters, your RSNetWorx for DeviceNet software is not version 3.00 or later.
Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter Appendix G If the 1769-ADN/A adapter does appear, double-click it and it will be placed on the network to the right as shown below. To configure I/O for the adapter, double-click the adapter that you just placed on the network, and this dialog box appears. At this point, you may modify the adapters DeviceNet node address, if desired.
Appendix G Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter Next, click the I/O Bank 1 Configuration tab. This dialog box appears. Configuring the 1769-IT6 Module 154 The 1769-ADN adapter appears in slot 0. Your I/O modules, power supplies, end cap, and interconnect cables must be entered in the proper order, following the 1769 I/O rules contained in the 1769-ADN user’s manual.
Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter Appendix G Slot 1 appears to the right of the 1769-IT6 module. Click this Slot 1 box and this 1769-IT6 configuration dialog box appears. By default, the 1769-IT6 module contains eight input words and no output words. Click Data Description.
Appendix G Configuring Your 1769-IT6 Module in a Remote DeviceNet System with a 1769-ADN DeviceNet Adapter This means that if an open-circuit condition should occur at any of the six thermocouple input channels, the input value for that channel is the full-scale value selected by the input type and data format. We can therefore monitor each channel for full scale (open-circuit) as well as monitor the Open-Circuit bits in input word 6, for each channel.
Glossary The following terms and abbreviations are used throughout this manual. For definitions of terms not listed here, refer to the Allen-Bradley Industrial Automation Glossary, publication AG-7.1. A/D converter Refers to the analog to digital converter inherent to the module. The converter produces a digital value whose magnitude is proportional to the magnitude of an analog input signal. attenuation The reduction in the magnitude of a signal as it passes through a system.
Glossary dB (decibel) A logarithmic measure of the ratio of two signal levels. digital filter A low-pass filter incorporated into the A/D converter. The digital filter provides very steep roll-off above it’s cut-off frequency, which provides high frequency noise rejection. effective resolution The number of bits in a channel configuration word that do not vary due to noise. filter A device that passes a signal or range of signals and eliminates all others.
Glossary module update time The time required for the module to sample and convert the input signals of all enabled input channels and make the resulting data values available to the processor. multiplexer An switching system that allows several signals to share a common A/D converter. normal mode rejection (differential mode rejection) A logarithmic measure, in dB, of a device’s ability to reject noise signals between or among circuit signal conductors.
Glossary Notes: 160 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Index Numerics -3 dB frequency 48 A A/D definition 157 abbreviations 157 accuracy 86 analog input module overview 11, 75 attenuation cut-off frequency 48 definition 157 autocalibration module update time 70 B before you begin 17 bus connector definition 157 locking 27 bus interface 14 C calibration 16 channel definition 157 channel configuration 40 channel configuration word 42 channel diagnostics 77 channel status indicator 14 channel step response effects of filter frequency 47 channel update time defi
Index filter frequency definition 158 effect on effective resolution 50 effect on noise rejection 46 effect on step response 47 selecting 46 finger-safe terminal block 33 full-scale definition 158 full-scale range definition 158 G gain drift definition 158 general status bits 39 grounding 20, 31 H hardware errors 79 heat considerations 25 I input data formats engineering units x 1 44 engineering units x 10 44 percent range 45 raw/proportional data 44 scaled for PID 45 input data scaling definition 158 i
Index scan time 158 spacing 28 specifications 83 start-up instructions 17 status indicator 75 status word definition 159 step response time definition 159 system operation 14 T terminal block removing 32 wiring 33 terminal door label 32 terminal screw torque 33 thermocouple accuracy 86 definition 159 descriptions 113 exposed junction 137 grounded junction 135 junction types 135 repeatability 85 ungrounded junction 137 using junctions 135 tools required for installation 17 troubleshooting safety considerat
Index Notes: 164 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
Index Notes: Rockwell Automation Publication 1769-UM004B-EN-P - March 2010 165
Index Notes: 166 Rockwell Automation Publication 1769-UM004B-EN-P - March 2010
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