MicroLogix™ 1200 RTD/Resistance Input Module (Catalog Number 1762-IR4) User Manual
Important User Information Because of the variety of uses for the products described in this publication, those responsible for the application and use of these products must satisfy themselves that all necessary steps have been taken to assure that each application and use meets all performance and safety requirements, including any applicable laws, regulations, codes and standards.
Table of Contents Preface Who Should Use This Manual . . . . . . . . . . . . . . How to Use This Manual . . . . . . . . . . . . . . . . . . Manual Contents . . . . . . . . . . . . . . . . . . . . . Related Documentation . . . . . . . . . . . . . . . . Conventions Used in This Manual . . . . . . . . . . . Rockwell Automation Support . . . . . . . . . . . . . . Your Questions or Comments on the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Table of Contents Chapter 3 Module Data, Status, and Channel Module Memory Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 Input Image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 Configuration Configuration File . . . . . . . . . . . . . . . . . . . . . . . . . . . . Accessing Input Image File Data . . . . . . . . . . . . . . . . . . . . Input Data File. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input Data Values . . . . . . . . . . . . . . . .
Table of Contents Power-up Diagnostics . . . . . . . . . . . . . . . . . Channel Diagnostics . . . . . . . . . . . . . . . . . . Invalid Channel Configuration Detection. Out-of-Range Detection . . . . . . . . . . . . . Open-Wire or Short-Circuit Detection . . . Non-critical vs. Critical Module Errors . . . . . Module Error Definition Table . . . . . . . . . . . Module Error Field. . . . . . . . . . . . . . . . . Extended Error Information Field . . . . . . Error Codes . . . . . . . . . . . . . . . . . . .
4 Table of Contents Publication 1762-UM003A-EN-P - February 2003
Preface Read this preface to familiarize yourself with the rest of the manual. This preface covers the following topics: • • • • • who should use this manual how to use this manual related publications conventions used in this manual Rockwell Automation support Who Should Use This Manual Use this manual if you are responsible for designing, installing, programming, or troubleshooting control systems that use MicroLogix 1200 controllers and 1762 Expansion I/O.
2 Preface Related Documentation The table below provides a listing of publications that contain important information about MicroLogix 1200 systems. For Read this document Document number A user manual containing information on how to install, MicroLogix™ 1200 User Manual use and program your MicroLogix 1200 controller 1762-UM001 An overview of the MicroLogix 1200 System, including 1762 Expansion I/O.
Preface Rockwell Automation Support 3 Rockwell Automation tests all of our products to ensure that they are fully operational when shipped from the manufacturing facility. If you are experiencing installation or startup problems, please review the troubleshooting information contained in this publication first. If you need technical assistance to get your module up and running, please contact Customer Support (see the table below); our trained technical specialists are available to help.
4 Preface Publication 1762-UM003A-EN-P - February 2003
Chapter 1 Overview This chapter describes the four-channel 1762-IR4 RTD/resistance Input module and explains how the controller reads resistance temperature detector (RTD) or direct resistance-initiated analog input data from the module. Included is: • a general description of hardware features • an overview of module and system operation • compatibility General Description The 1762-IR4 module supports RTD and direct resistance signal measurement applications that require up to four channels.
1-2 Overview The following data formats are supported by the module.: • • • • • raw/proportional engineering units x 1 engineering units x 10 scaled-for-PID percent full scale Available filter frequencies are: • • • • • • 10 Hz 50 Hz 60 Hz 250 Hz 500 Hz 1 kHz The module uses six input words for data and status bits and five configuration words. Module configuration is stored in the controller memory. Normally configuration is done via the controller’s programming software.
Overview 1-3 Table 1.1 RTD Specifications RTD Type(1) Temperature Range Using 0.5 mA Excitation Temperature Range Using 1.0 mA Excitation Maximum Scaled Resolution Maximum Scaled Repeatability Copper 426 10Ω Not allowed -100 to 260°C (-148 to 500°F) 0.1°C (0.1°F) ±0.2°C (±0.4°F) Nickel 618(2) 120Ω -100 to 260°C (-148 to 500°F) -100 to 260°C (-148 to 500°F) 0.1°C (0.1°F) ±0.1°C (±0.2°F) Nickel 672 120Ω -80 to 260°C (-112 to 500°F) -80 to 260°C (-112 to 500°F) 0.1°C (0.1°F) ±0.1°C (±0.
1-4 Overview The tables below provide specifications for RTD accuracy and temperature drift. Table 1.2 RTD Accuracy and Temperature Drift RTD Type Maximum Scaled Accuracy (25°C with Calibration) Maximum Scaled Accuracy (0 to 55°C with Calibration) Maximum Temperature Drift (from 25°C without Calibration) Copper 426 10Ω ±0.6°C (1.08°F) ±1.1°C (1.98°F) ±0.032°C/°C (0.032°F/°F) Nickel 618 120Ω ±0.2°C (±0.36°F) ±0.4° C (±0.72°F) ±0.012°C/° C (±0.012°F/°F) Nickel 672 120Ω ±0.2°C (±0.36°F) ±0.
Overview 1-5 Resistance Device Compatibility The following table lists the specifications for the resistance devices that you can use with the module. Table 1.3 Resistance Device Specifications Resistance Device Type Resistance Range (0.5 mA Excitation) Resistance Range (1.0 mA Excitation) Accuracy(1) Temperature Drift Resolution Repeatability 150Ω 0 to 150Ω 0 to 150Ω ±0.15Ω ±0.007Ω/°C (±0.012Ω/°F) 0.01Ω ±0.04Ω 500Ω 0 to 500Ω 0 to 500Ω ±0.5Ω ±0.023Ω/°C (±0.041Ω/°F) 0.1Ω ±0.
1-6 Overview Hardware Features The RTD/resistance module provides connections for four 3-wire inputs for any combination of RTD and resistance input devices. Channels are wired as differential inputs. The illustration below shows the hardware features of the module.
Overview System Overview 1-7 The modules communicate to the local controller or communication adapter through the 1762 bus interface. The modules also receive 5 and 24V dc power through the bus interface. System Operation At power-up, the module performs a check of its internal circuits, memory, and basic functions. During this time, the module status LED remains off. If no faults are found during power-up diagnostics, the module status LED is turned on.
1-8 Overview Module Operation As shown in the block diagram below, each input channel of the module consists of an RTD/resistance connection that accepts excitation current; a sense connection that detects lead wire resistance; and a return connection. The signals are multiplexed to an A/D converter that reads the RTD or resistance value and the lead wire resistance.
Chapter 2 Installation and Wiring This chapter tells you how to: • • • • • Compliance to European Union Directives determine the power requirements for the modules avoid electrostatic damage install the module wire the module’s terminal block wire input devices This product is approved for installation within the European Union and EEA regions. It has been designed and tested to meet the following directives.
2-2 Installation and Wiring For specific information required by EN61131-2, see the appropriate sections in this publication, as well as the following Allen-Bradley publications: • Industrial Automation, Wiring and Grounding Guidelines for Noise Immunity, publication 1770-4.1 • Automation Systems Catalog, publication B113 Power Requirements The module receives +5V dc and 24V dc power from the system power supply through the bus interface.
Installation and Wiring 2-3 Hazardous Location Considerations This equipment is suitable for use in Class I, Division 2, Groups A, B, C, D or non-hazardous locations only. The following WARNING statement applies to use in hazardous locations. WARNING ! EXPLOSION HAZARD • Substitution of components may impair suitability for Class I, Division 2. • Do not replace components or disconnect equipment unless power has been switched off or the area is known to be non-hazardous.
2-4 Installation and Wiring Remove Power ATTENTION ! Remove power before removing or inserting this module. When you remove or insert a module with power applied, an electrical arc may occur.
Installation and Wiring 2-5 Mounting ATTENTION ! Do not remove protective debris strip until after the module and all other equipment near the module is mounted and wiring is complete. Once wiring is complete and the module is free of debris, carefully remove the protective debris strip. Failure to remove the strip before operating can cause overheating. Minimum Spacing Maintain spacing from enclosure walls, wireways, adjacent equipment, etc. Allow 50.8 mm (2 in.
2-6 Installation and Wiring DIN Rail Mounting The module can be mounted using the following DIN rails: 35 x 7.5 mm (EN 50 022 - 35 x 7.5) or 35 x 15 mm (EN 50 022 - 35 x 15). Before mounting the module on a DIN rail, close the DIN rail latch. Press the DIN rail mounting area of the module against the DIN rail. The latch will momentarily open and lock into place. Use DIN rail end anchors (Allen-Bradley part number 1492-EA35 or 1492-EAH35) for environments with vibration or shock concerns.
Installation and Wiring 2-7 For more than 2 modules: (number of modules - 1) x 40.4 mm (1.59 in.) MicroLogix 1200 Expansion I/O MicroLogix 1200 Expansion I/O NOTE: Hole spacing tolerance: ±0.4 mm (0.016 in.). 40.4 (1.59) MicroLogix 1200 Expansion I/O 100 90 (3.94) (3.54) MicroLogix 1200 14.5 (0.57) 40.4 (1.59) System Assembly The expansion I/O module is attached to the controller or another I/O module by means of a ribbon cable after mounting as shown below.
2-8 Installation and Wiring Field Wiring Connections System Wiring Guidelines Consider the following when wiring your system: General • This product is intended to be mounted to a well-grounded mounting surface such as a metal panel. Additional grounding connections from the module’s mounting tabs or DIN rail (if used) are not required unless the mounting surface cannot be grounded. • Channels are isolated from one another by ±10V dc maximum. • Do not use the modules NC terminals as connection points.
Installation and Wiring 2-9 • Keep shield connection to ground as short as possible. • If noise persists for a device, try grounding the opposite end of the cable. (You can only ground one end at a time.) • Refer to Industrial Automation Wiring and Grounding Guidelines, Allen-Bradley publication 1770-4.1, for additional information. RTD Wiring Considerations Since the operating principle of the RTD module is based on the measurement of resistance, take special care when selecting your input cable.
2-10 Installation and Wiring Wiring the Finger-Safe Terminal Block ATTENTION ! Be careful when stripping wires. Wire fragments that fall into a module could cause damage when power is applied. Once wiring is complete, ensure the module is free of all metal fragments. When wiring the terminal block, keep the finger-safe cover in place. 1. Route the wire under the terminal pressure plate. You can use the stripped end of the wire or a spade lug. The terminals will accept a 6.35 mm (0.25 in.) spade lug. 2.
Installation and Wiring 2-11 Wire Size and Terminal Screw Torque Each terminal accepts up to two wires with the following restrictions: Wire Type Wire Size Terminal Screw Torque Solid Cu-90°C (194°F) #14 to #22 AWG 0.904 Nm (8 in-lbs) Stranded Cu-90°C (194°F) #16 to #22 AWG 0.904 Nm (8 in-lbs) Wiring Input Devices to the Module ATTENTION ! To prevent shock hazard, care should be taken when wiring the module to analog signal sources.
2-12 Installation and Wiring To wire your module follow these steps: 1. At each end of the cable, strip some casing to expose the individual wires. 2. Trim the signal wires to 2-inch (5 cm) lengths. Strip about 3/16 inch (5 mm) of insulation away to expose the end of the wire. ATTENTION Be careful when stripping wires. Wire fragments that fall into a module could cause damage at power up. ! 3.
Installation and Wiring 2-13 2-Wire RTD Configuration Cable Shield (to Ground) RTD EXC RTD EXC EXC 2 Return Return SENSE 2 RTN 2 Belden 9501 Shielded Cable NC IMPORTANT Using 2-wire configurations does not permit the module to compensate for resistance error due to lead wire length. The resulting analog data includes the effect of this uncompensated lead wire resistance.
2-14 Installation and Wiring 4-Wire RTD Configuration Cable Shield (to Ground) RTD EXC RTD EXC EXC 2 Sense Sense Return Return SENSE 2 RTN 2 NC Belden 83503 or 9533 Shielded Cable Leave one sensor wire open. Wiring Resistance Devices (Potentiometers) Potentiometer wiring requires the same type of cable as that for the RTDs described on page 2-9. Potentiometers can be connected to the module as a 2-wire or 3-wire connection as shown on page 2-14.
Installation and Wiring 2-15 Using 2-wire configurations does not permit the module to compensate for resistance error due to lead wire length. The resulting analog data includes the effect of this uncompensated lead wire resistance. The module continues to place the uncompensated analog data in the input data file, but the open-circuit status bit (OCx) is set in word 4 of the input data file for any enabled channel using a 2-wire configuration.
2-16 Installation and Wiring Publication 1762-UM003A-EN-P - February 2003
Chapter 3 Module Data, Status, and Channel Configuration After installing the 1762-IR4 RTD/resistance input module, you must configure it for operation, usually using the programming software compatible with the controller (for example, RSLogix 500™). Once configuration is complete and reflected in ladder logic, you will need to get the module up and running and then verify its operation.
3-2 Module Data, Status, and Channel Configuration Input Image The input image file represents data words and status words. Input words 0 through 3 hold the input data that represents the value of the analog inputs for channels 0 through 3. These data words are valid only when the channel is enabled and there are no errors. Input words 4 and 5 hold the status bits. To receive valid status information, the channel must be enabled.
Module Data, Status, and Channel Configuration 3-3 Input Data File The input data table allows you to access RTD input module read data for use in the control program, via word and bit access. The data table structure is shown in table below. Table 3.
3-4 Module Data, Status, and Channel Configuration Input Data Not Valid Condition The general status bits S0 to S3 also indicate whether or not the input data for a particular channel, 0 through 3, is being properly converted (valid) by the module. This “invalid data” condition can occur (bit set) when the download of a new configuration to a channel is accepted by the module (proper configuration) but before the A/D converter can provide valid (properly configured) data to the MicroLogix 1200 controller.
Module Data, Status, and Channel Configuration 3-5 Over-Range Flag Bits (O0 to O3) Over-range bits for channels 0 through 3 are contained in word 5, even-numbered bits. They apply to all input types. When set (1), the over-range flag bit indicates an RTD temperature that is greater than the maximum allowed temperature or a resistance input that is greater than the maximum allowed resistance for the module.
3-6 Module Data, Status, and Channel Configuration Configuration Data File The configuration data file is shown below. Bit definitions are provided in Channel Configuration on page 3-7. Detailed definitions of each of the configuration parameters follows the table. TIP Normal channel configuration is done using programming software. In that case, it is not necessary to know the meaning of the bit location. However, some systems allow configuration to be changed by the control program.
Module Data, Status, and Channel Configuration 3-7 The following table shows the basic arrangement of the configuration data file. Table 3.
3-8 Module Data, Status, and Channel Configuration Table 3.4 Channel Configuration Bit Definitions To Select Filter Frequency Excitation Current Cyclic Lead Compensation Open/Broken Circuit Response Temperature Units/Mode(1) Make these bit settings 15 14 13 12 11 10 10 Hz 60 Hz 50 Hz 250Hz 500 Hz 1 kHz 1.0 mA 0.
Module Data, Status, and Channel Configuration 3-9 Enabling or Disabling a Channel (Bit 15) Bit 15 enables or disables each of the six channels individually. The module only scans those channels that are enabled. Enabling a channel forces it to be recalibrated before it measures input data. Turning a channel off results in the channel data being set to zero. TIP When a channel is not enabled, the A/D converter provides no input to the controller. This speeds up the system response of the active channels.
3-10 Module Data, Status, and Channel Configuration Table 3.5 Data Formats for RTD Temperature Ranges for 0.5 and 1.0 mA Excitation Current Data Format RTD Input Type Engineering Units x1 0.1°C 0.1°F Engineering Units x10 1.0°C 1.
Module Data, Status, and Channel Configuration 3-11 Figure 3.1 Linear Relationship Between Temperature and Proportional Counts Counts + 32,767 ±200 ˚C °C 850 ˚C -32,768 The value +32767 corresponds to the highest value for the device. For example, if a 100Ω platinum 385 RTD is selected, the lowest temperature of -200° C corresponds to -32768 counts. The highest temperature of 850° C corresponds to +32767 counts. See Determining Effective Resolution and Range on page 3-20.
3-12 Module Data, Status, and Channel Configuration Engineering Units x1 to Scaled-for-PID EXAMPLE • input type = 200Ω Platinum RTD • α = 0.00385°C • range = -200 to +850°C SLOW = -200°C SHIGH = +850°C • desired channel temperature = 344°C (engineering units) Scaled-for-PID Equivalent = 16383 x [(desired ch. temp.
Module Data, Status, and Channel Configuration 3-13 Engineering Units x 1 Data Format If you select engineering units x 1 as the data format for an RTD input, the module scales input data to the actual temperature values for the selected RTD type per RTD standard. It expresses temperatures in 0.1° C units. For resistance inputs, the module expresses resistance in 0.1Ω units, for all ranges except the 150Ω range. For the latter, resistance is expressed in 0.01Ω units.
3-14 Module Data, Status, and Channel Configuration Linear Relationship Between Temperature and PID Counts Counts +16383 °C -200 ˚C +850 ˚C The amount over and under user range (full-scale range -410 to +16793) is also included in the signed integer provided to the controller. Allen-Bradley controllers, such as the MicroLogix 1500, use this range in their PID equations. See Determining Effective Resolution and Range on page 3-20.
Module Data, Status, and Channel Configuration 3-15 Selecting Temperature Units/Mode (Bit 7) The module supports two different linearized, scaled temperature ranges for RTDs, degrees Celsius (°C) and degrees Fahrenheit (°F). You can select the type that is appropriate for your application by setting bit 7 in the channel configuration word. Bit 7 is ignored for resistance input types or when raw/proportional, scaled-for-PID, or percent data formats are used.
3-16 Module Data, Status, and Channel Configuration Selecting Cyclic Lead Compensation (Bit 4) For each channel, the module measures lead resistance in one of two ways. Set bit 4 to 0 to enable measurement and compensation of lead resistance every five minutes. One channel is measured per module update to limit the impact to channel throughput. You can also implement a lead wire calibration cycle any time, at your command, by enabling and then disabling this bit in your control program.
Module Data, Status, and Channel Configuration 3-17 The choice that you make for filter frequency will affect: • • • • • • noise rejection characteristics for module input channel step response channel cutoff frequency module autocalibration effective resolution module update time Effects of Filter Frequency on Noise Rejection The filter frequency that you choose for a channel determines the amount of noise rejection for the inputs. A smaller filter frequency (e.g.
3-18 Module Data, Status, and Channel Configuration the channel filter. The channel step response is calculated by a settling time of 3 x (1 / filter frequency). Table 3.7 Filter Frequency vs.
Module Data, Status, and Channel Configuration 3-19 Frequency Response Graphs 10 Hz Input Filter Frequency 50 Hz Input Filter Frequency 0 –3 dB –20 –20 –40 –40 –60 –60 –80 –80 Gain (dB) Gain (dB) 0 -100 -120 -100 -120 -140 -140 -160 -160 -180 -180 - 200 - 200 0 10 30 20 50 40 60 0 Frequency (Hz) 2.62 Hz –3 dB 50 13.
3-20 Module Data, Status, and Channel Configuration Selecting Enable/Disable Cyclic Autocalibration (Word 4, Bit 0) Configuration word 4, bit 0 allows you to configure the module to perform an autocalibration cycle of all enabled channels once every 5 minutes. Cyclic calibration functions to reduce offset and gain drift errors due to temperature changes within the module. Setting this bit to 1 disables cyclic calibration, the default (0) enables the autocalibration function.
Module Data, Status, and Channel Configuration 3-21 Table 3.9 Effective Resolution and Range for 10 Hz Filter Frequency °C °F °C °F Resolution °C °F Percent of Full Scale 0 to 100% Decimal Range °F Resolution Decimal Range °C Resolution Engineering Units x 10 Scaled for PID Over Full Over Full Range Range Decimal Range Resolution Engineering Units x 1 Over Full Range Decimal Range Input Type Decimal Range Raw/Proportional Data Over Full Input Range Resolution °C °F -2000 to +8500 0.
3-22 Module Data, Status, and Channel Configuration Table 3.10 Effective Resolution and Range for 50-60 Hz Filter Frequency °F Decimal Range -2000 to +8500 0.3°C / 3 counts 0.540°F/ 3 counts -200 to +850 1.0°C/ 1 count 1.8°F/ 1 count 0.256°C/4 0.461°F/ counts 4 counts 0.315°C/ 3 counts 0.567°F/ 3 counts 200Ω Pt 385 0.112°C / 7 counts 0.202°F/ 7 counts -2000 to +8500 0.2°C / 2 counts 0.360°F/ 2 counts -200 to +850 1.0°C/ 1 count 1.8°F/ 1 count 0.128°C/ 2 counts 0.231°F/ 2 counts 0.
Module Data, Status, and Channel Configuration 3-23 Table 3.11 Effective Resolution and Range for 250 Hz Filter Frequency Resolution Resolution °F 100Ω Pt 385 0.224°C/ 14 counts 0.404°F/ 14 counts -2000 to +8500 0.3°C/ 3 0.540°F/ -200 counts 3 counts to +850 1.0°C/ 1.8°F/1 1 count count 0.256°C/ 4 counts 0.461°F/ 4 counts 0.315°C/ 3 counts 0.567°F/ 3 counts 200Ω Pt 385 0.224°C/ 14 counts 0.404°F/ 14 counts -2000 to +8500 0.3°C/ 3 0.540°F/ -200 counts 3 counts to +850 1.0°C/ 1 count 1.
3-24 Module Data, Status, and Channel Configuration Table 3.12 Effective Resolution and Range for 500 Hz Filter Frequency °C °F °C °F Resolution °C °F Percent of Full Scale 0 to 100% Decimal Range °F Resolution Decimal Range °C Resolution Engineering Units x 10 Scaled for PID Over Full Over Full Range Range Decimal Range Resolution Engineering Units x 1 Over Full Range Decimal Range Input Type Decimal Range Raw/Proportional Data Over Full Input Range Resolution °C °F 6.900°C/ 12.
Module Data, Status, and Channel Configuration 3-25 Table 3.13 Effective Resolution and Range for 1 kHz Filter Frequency °C °F °C °F Resolution °C °F Percent of Full Scale 0 to 100% Decimal Range °F Resolution Decimal Range °C Resolution Decimal Range Resolution Engineering Units x 1 Over Engineering Units x 10 Scaled for PID Over Full Full Range Over Full Range Range Decimal Range Decimal Range Input Raw/Proportional Data Type Over Full Input Range Resolution °C °F -200 to +850 7.
3-26 Module Data, Status, and Channel Configuration The table below identifies the number of significant bits used to represent the input data for each available filter frequency. The number of significant bits is defined as the number of bits that will have little or no jitter due to noise, and is used in defining the effective resolution. Note that the resolutions provided by the filters apply to the raw/proportional data format only. Table 3.
Module Data, Status, and Channel Configuration Determining Module Update Time 3-27 The module update time is defined as the time required for the module to sample and convert the input signals of all enabled input channels and provide the resulting data values to the processor. The module sequentially samples the channels in a continuous loop as shown below.
3-28 Module Data, Status, and Channel Configuration Module update time can be calculated by obtaining the sum of all enabled channel update times. Channel update times include channel scan time, channel switching time, and reconfiguration time. EXAMPLE 1. Module Update Time with all channels enabled and configured with 10 Hz filter = 4 x 303 ms = 1212 ms 2.
Module Data, Status, and Channel Configuration 3-29 Calculating Module Update Time with Autocalibration Enabled The following example illustrates how to determine module update time with autocalibration enabled. EXAMPLE zews Two Channels Enabled with Cyclic Calibration Channel 0 Input: 100Ω Platinum 385, 1.0 mA source with 60 Hz Filter Channel 1 Input: 100Ω Platinum 385, 0.5 mA source with 60 Hz Filter From Table 3.15, Channel Update Time vs. Filter Frequency, on page 3-27: 1.
3-30 Module Data, Status, and Channel Configuration Effects of Cyclic Lead Wire Compensation on Module Update Time The 1762-IR4 module provides the option to enable lead wire compensation for each channel. This feature improves measurement accuracy for 3- and 4-wire RTDs by compensating for the resistance of the RTD lead wire. Lead wire compensation occurs automatically on a mode change from Program-to-Run for all configured channels regardless of the type of RTD being used.
Module Data, Status, and Channel Configuration 3-31 Calculating Module Update Time with Cyclic Lead Wire Compensation Enabled The following example illustrates how to determine module update time with cyclic lead wire compensation enabled. EXAMPLE Two Channels Configured with Cyclic Lead Wire Compensation Enabled Channel 0 Input: 100Ω Platinum 385 with 60 Hz Filter (use 60 Hz filter for lead wire) Channel 1 Input: 100Ω Platinum 385 with 250 Hz Filter (use 250 Hz filter for lead wire) From Table 3.
3-32 Module Data, Status, and Channel Configuration Impact of Autocalibration and Lead Wire Compensation on Module Startup Regardless of the selection of the Enable/Disable Cyclic Calibration and Enable/Disable Cyclic Lead Calibration functions, a cycle of both of these functions occurs automatically on a mode change from Program-to-Run and on subsequent module startups/initialization for all configured channels.
Module Data, Status, and Channel Configuration Effects of Autocalibration on Accuracy 3-33 The module performs autocalibration to correct for drift errors over temperature. Autocalibration occurs immediately following configuration of a previously unselected channel, during power cycle of enable channels and every 5 minutes if so configured. The table below shows module accuracy with and without calibration. Table 3.
3-34 Module Data, Status, and Channel Configuration Publication 1762-UM003A-EN-P - February 2003
Chapter 4 Diagnostics and Troubleshooting This chapter describes module troubleshooting, containing information on: • • • • • • Safety Considerations safety considerations when troubleshooting module vs. channel operation the module’s diagnostic features critical vs. non-critical errors module condition data contacting Rockwell Automation for assistance Safety considerations are an important element of proper troubleshooting procedures.
4-2 Diagnostics and Troubleshooting Activating Devices When Troubleshooting When troubleshooting, never reach into the machine to actuate a device. Unexpected machine motion could occur. Stand Clear of the Equipment When troubleshooting any system problem, have all personnel remain clear of the equipment. The problem could be intermittent, and sudden unexpected machine motion could occur. Have someone ready to operate an emergency stop switch in case it becomes necessary to shut off power.
Diagnostics and Troubleshooting 4-3 Internal diagnostics are performed at both levels of operation. When detected, module error conditions are immediately indicated by the module status LED. Both module hardware and channel configuration error conditions are reported to the controller. Channel over-range or under-range conditions are reported in the module’s input data table. Module hardware errors are reported in the controller’s I/O status file. Refer to your controller manual for details.
4-4 Diagnostics and Troubleshooting Possible causes for an out-of-range condition include: • The temperature is too hot or too cold for the RTD being used. • The wrong RTD is being used for the input type selected, or for the configuration that you have programmed. • The input device is faulty. • The signal input from the input device is beyond the scaling range. Open-Wire or Short-Circuit Detection The module performs an open-circuit or short-circuit input test on all enabled channels on each scan.
Diagnostics and Troubleshooting Module Error Definition Table 4-5 Module errors are expressed in two fields as four-digit Hex format with the most significant digit as irrelevant (“don’t care”). The two fields are “Module Error” and “Extended Error Information”. The structure of the module error data is shown below. Table 4.
4-6 Diagnostics and Troubleshooting 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 1762 analog modules. TIP If no errors are present in the module error field, the extended error information field will be set to zero.
Diagnostics and Troubleshooting Error Codes 4-7 The table below explains the extended error code. Table 4.
4-8 Diagnostics and Troubleshooting Module Inhibit Function Whenever the 1762-IR4 module is inhibited, the module continues to provide information about changes at its inputs to the MicroLogix 1200 controller. Contacting Rockwell Automation If you need to contact Rockwell Automation for assistance, please have the following information available when you call: • a clear statement of the problem, including a description of what the system is actually doing.
Appendix A Specifications General Specifications Specification Value Dimensions 90 mm (height) x 87 mm (depth) x 40 mm (width) height including mounting tabs is 110 mm 3.54 in. (height) x 3.43 in (depth) x 1.58 in (width) height including mounting tabs is 4.33 in. Approximate Shipping Weight (with carton) 260g (0.57 lbs.
A-2 Specifications Input Specifications Specification Input Types 1762-IR4 • • • • • • • • • • • • • • • • 100Ω Platinum 385 200Ω Platinum 385 500Ω Platinum 385 1000Ω Platinum 385 100Ω Platinum 3916 200Ω Platinum 3916 500Ω Platinum 3916 1000Ω Platinum 3916 10Ω Copper 426 120Ω Nickel 672 120Ω Nickel 618 604Ω Nickel-Iron 518 0 to 150Ω 0 to 500Ω 0 to 1000Ω 0 to 3000Ω Bus Current Draw (max.) 40 mA at 5V dc 50 mA at 24V dc Heat Dissipation 1.
Specifications Specification 1762-IR4 Accuracy Drift at 0 to 55° C (+32 to +131°F) ±0.026°C/°C (0.026°F/°F) for Pt 385 ±0.023°C/°C (0.023°F/°F) for Pt 3916 ±0.012°C/°C (0.012°F/°F) for Ni ±0.015°C/°C (0.015°F/°F) for NiFe ±0.032°C/°C (0.032°F/°F) for Cu Repeatability(1) ±0.1°C (±0.18°F) for Ni and NiFe ±0.2°C (±0.36°F) to ±0.2°C (±0.36°F) for other RTD inputs ±0.04Ω for 150Ω resistances ±0.2Ω for other resistances Excitation Current Source A-3 ±0.007Ω/°C (0.012Ω/°F) for 150Ω range ±0.023Ω/°C (0.
A-4 Specifications Cable Specifications Description Belden #9501 Belden #9533 Belden #83503 When used? For 2-wire RTDs and potentiometers. For 3-wire RTDs and potentiometers. Short runs less than 100 feet and normal humidity levels. For 3-wire RTDs and potentiometers. Long runs greater than 100 feet or high humidity levels.
Appendix C 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.
C-2 Two’s Complement Binary Numbers Negative Decimal Values In two’s complement notation, the far left position is always 1 for negative values. The equivalent decimal value of the binary number is obtained by subtracting the value of the far left position, 32768, from the sum of the values of the other positions. In the figure below (all positions are 1), the value is 32767 - 32768 = -1.
Appendix B Configuring the 1762-IR4 Module Using RSLogix 500 This appendix examines the 1762-IR4 module’s addressing scheme and describes module configuration using RSLogix 500. Module Addressing The following memory map shows the input image table for the module. Detailed information on the image table is located in Chapter 3.
B-2 Configuring the 1762-IR4 Module Using RSLogix 500 The default configuration is as follows: Table B.1 Default Configuration Configuration Using RSLogix 500 Version 5.50 or Higher Parameter Default Setting Channel Enable/Disable Disable Input Type 100Ω Platinum 385 Data Format Raw/Proportional Temperature Units °C (not applicable with Raw/Proportional) Broken Input Upscale Disable Cyclic Lead Compensation Enable Excitation Current 1.
Configuring the 1762-IR4 Module Using RSLogix 500 B-3 While offline, double-click on the IO Configuration icon under the controller folder and the following IO Configuration screen appears. This screen allows you to manually enter expansion modules into expansion slots, or to automatically read the configuration of the controller. To read the existing controller configuration, click on the Read IO Config button.
B-4 Configuring the 1762-IR4 Module Using RSLogix 500 The 1762-IR4 module is installed in slot 1. To configure the module, double-click on the module/slot. The general configuration screen appears. Configuration options for channels 0 to 2 are located on a separate tab from channel 3, as shown below. To enable a channel, click its Enable box so that a check mark appears in it. For optimum module performance, disable any channel that is not hard wired to a real input.
Configuring the 1762-IR4 Module Using RSLogix 500 B-5 Use the Calibration tab (Cal) to disable cyclic calibration. For more information on the autocalibration feature, see Selecting Enable/Disable Cyclic Autocalibration (Word 4, Bit 0) on page 3-20. Generic Extra Data Configuration This tab re-displays the configuration information entered on the Analog Input Configuration screen in a raw data format.
B-6 Configuring the 1762-IR4 Module Using RSLogix 500 Configuration Using RSLogix 500 Version 5.2 or Lower If you do not have version 5.5 or higher of RSLogix 500, you can still configure your module, using the Generic Extra Data Configuration dialog. To configure the 1762-IR4, select "Other -- Requires I/O Card Type ID" from the I/O Configuration dialog. The following screen appears. Enter the I/O module information as shown.
Configuring the 1762-IR4 Module Using RSLogix 500 B-7 Enter -15597 into the Generic Extra Data Config Tab as shown below.
B-8 Configuring the 1762-IR4 Module Using RSLogix 500 Publication 1762-UM003A-EN-P - February 2003
Glossary The following terms and abbreviations are used throughout this manual. For definitions of terms not listed here refer to Allen-Bradley’s 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.
2 Glossary common mode voltage range The largest voltage difference allowed between either the positive or negative terminal and analog common during normal differential operation. configuration word Word containing the channel configuration information needed by the module to configure and operate each channel. cut-off frequency The frequency at which the input signal is attenuated 3 dB by a digital filter.
Glossary 3 filter A device that passes a signal or range of signals and eliminates all others. filter frequency The user-selectable frequency for a digital filter. full-scale The magnitude of input over which normal operation is permitted. full-scale range The difference between the maximum and minimum specified analog input values for a device. gain drift Change in full-scale transition voltage measured over the operating temperature range of the module.
4 Glossary full-scale input. See the variation from the straight line due to linearity error (exaggerated) in the example below. Actual Transfer Function Ideal Transfer LSB Least significant bit. The LSB represents the smallest value within a string of bits. For analog modules, 16-bit, two’s complement binary codes are used in the I/O image. For analog inputs, the LSB is defined as the rightmost bit of the 16-bit field (bit 0).
Glossary 5 overall accuracy The worst-case deviation of the digital representation of the input signal from the ideal over the full input range is the overall accuracy. Overall accuracy is expressed in percent of full scale. repeatability The closeness of agreement among repeated measurements of the same variable under the same conditions. resolution The smallest detectable change in a measurement, typically expressed in engineering units (e.g. 1°C) or as a number of bits.
6 Glossary Publication 1762-UM003A-EN-P - February 2003
Index A A/D definition G-1 A/D converter 1-8, 3-9 abbreviations G-1 accuracy autocalibration 3-33 module 3-33 overall 1-4 resistance device 1-5 addressing 3-1 analog input module overview 4-1 attenuation 3-18 definition G-1 autocalibration 3-20, 3-33 B broken input detection 4-4 downscale 3-15 last state 3-15 upscale 3-15 zero 3-15 bus connector 1-6 definition G-1 bus interface 1-7 C calibration 3-20, 3-33 channel 1-8 definition G-1 channel cutoff frequency 3-17, 3-18 channel diagnostics 4-3 channel enabl
2 Index E effective resolution 1 kHz 3-25 10 Hz 3-21 250 Hz 3-23 500 Hz 3-24 50-60 Hz 3-22 definition G-2 number of significant bits 3-26 electrical noise 2-4 EMC Directive 2-1 engineering units x 1 3-13 engineering units x 10 3-13 error codes 4-7 error definitions 4-5 errors configuration 4-6 critical 4-4 extended error information field 4-6 hardware 4-6 module error field 4-5 non-critical 4-4 European Union Directives 2-1 excitation connections 1-8 excitation current 1-8, 3-16 definition G-2 extended er
Index multiplexer definition G-4 multiplexing 1-8 N negative decimal values C-2 noise 3-17 noise rejection 3-17 normal mode rejection definition G-4 number of significant bits 3-26 definition G-4 O open circuit 3-15 open-circuit bits 3-4 operation system 1-7 out-of range detection 4-3 overall accuracy definition G-5 over-range flag bits 3-5 P panel mounting 2-6–2-7 percent of full scale 3-14 periodic calibration 3-20, 3-33 PID 3-13 positive decimal values C-1 power-up diagnostics 4-3 power-up sequence 1
4 Index W wiring 2-1 input devices 2-11 routing considerations 2-4 Publication 1762-UM003A-EN-P - February 2003 terminal block 2-10 terminal screw torque 2-11 wire size 2-11
Publication 1762-UM003A-EN-P - February 2003 9 Copyright © 2003 Rockwell Automation, Inc. All rights reserved. Printed in the U.S.A.
