M2A Transmitter Operator’s Manual Part Number: 71-0305RK Revision: P2 Released: 6/26/14 RKI Instruments, Inc. www.rkiinstruments.
WARNING Read and understand this instruction manual before operating instrument. Improper use of the gas monitor could result in bodily harm or death. Periodic calibration and maintenance of the gas monitor is essential for proper operation and correct readings. Please calibrate and maintain this instrument regularly! Frequency of calibration depends upon the type of use you have and the sensor types.
Product Warranty RKI Instruments, Inc. warrants gas alarm equipment sold by us to be free from defects in materials, workmanship, and performance for a period of one year from date of shipment from RKI Instruments, Inc. Any parts found defective within that period will be repaired or replaced, at our option, free of charge.
Table of Contents Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 About the M2A Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 About this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 7: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1: Introduction Overview This chapter briefly describes the M2A Transmitter. This chapter also describes the M2A Transmitter Operator’s Manual (this document). Table 1 at the end of this chapter lists the specifications for the M2A. About the M2A Transmitter The M2A transmitter is a fixed mount, continuous-monitoring detector head. All user adjustable parameters may be accessed using push button switches.
Specifications Table 1 lists specifications for the M2A. Table 1: M2A Specifications Target Gas/Detection Range Combustible Gas/Carbon Dioxide (CO2) • Catalytic LEL: 0 - 100% LEL, 1% LEL increments (CH4 calibration unless otherwise specified.
Table 1: M2A Specifications Input Power 10 - 30 VDC Controls • • Weight 4.5 lbs.
Chapter 2: Description Overview This chapter describes external and internal components of the M2A Transmitter. External Description This section describes the junction box and all external components of the M2A transmitter. 3/4 NPT Conduit Hub, Plugged Junction Box Cover Mounting Slot (2x) Magnetic W and W indow 3/4 NPT Conduit Hub Detector (Catalytic LEL Detector Shown) Figure 1: M2A External Components Junction Box The M2A’s cast aluminum junction box is dust and weather resistant.
Use the junction box’s two mounting holes to mount the M2A to a vertical surface at the monitoring site. The window in the cover on the front of the junction box allows you to view the OLED display and use the magnetic wand to actuate the magnetic control switches so you can perform non-intrusive calibration. Removing the cover allows you to access the interior of the junction box. Magnetic Wand The magnetic wand is a short plastic rod with a magnet in one end.
Table 2: M2A Detectors Target Gas, Range Detector(s) Used Cl2, 0 - 3 ppm • 65-2300RK-CL2 Cl2, 0 - 10 ppm • 65-2300RK-CL-10 PH3, 0 - 1 ppm • 65-2300RK-PH3 SO2, 0 - 6 ppm • 65-2300RK-SO2 Catalytic LEL Detectors The catalytic LEL detectors have a 1/2” NPT thread and require a 3/4”NPT x 1/2”NPT reducer to install in the detector hub. The rest of the detectors have a 3/4” NPT mounting thread and are installed directly in the detector hub.
Detector Housing Body Cap Gasket Plug-In Oxygen Sensor Detector Housing Cap Hydrophobic Membrane Figure 3: 65-2494RK Oxygen Detector, Non-Explosion Proof, Capillary Type CO and H2S Detectors Both types of CO and H2S detectors have replaceable plug-in sensors inside the detector housing. The CO detector includes a charcoal filter disk which is held onto the sensor with a rubber retaining boot.
Detector Housing Body Cap Gasket CO Plug-in Sensor Charcoal Filter w/Rubber Boot Detector Housing Cap Hydrophobic Membrane Figure 5: 65-2496RK CO Detector Non-Explosion Proof Detector Housing Body Cap Gasket H2S Plug-in Sensor Spacer Rubber Boot Detector Housing Cap Flame Arrestor Guard Figure 6: 65-2423RK-05 H2S Detector, CSA M2A Transmitter Operator’s Manual 8
Detector Housing Body Cap Gasket H2S Plug-in Sensor Detector Housing Cap Hydrophobic Membrane Figure 7: 65-2495RK H2S Detector Non-Explosion Proof ESM-01 Detectors The construction of the various ESM-01 detectors is similar. Each of the ESM-01 detectors has a different replaceable plug-in sensor that protrudes through the detector housing cap.
Internal Description This section describes the internal components of the M2A. The internal components of the M2A include the terminal PCB which provides for all the wiring connections to the M2A and the control PCB which displays the gas reading and has the control buttons.
to program the M2A. On the combustible and CO2 versions of the M2A, a factory adjust pot just above the programming connector is used to set the detector current. Power/Signal Terminal Strip The power/signal terminal strip is a three position plug-in style terminal strip located at the top of the left terminal column. It is used to connect 24 VDC power to the M2A and to connect the 4 - 20 mA output signal to a device. The signal output, the S terminal, does not have to be connected for the M2A to function.
Relay Terminal Strips The right column of terminal strips consists of, from top to bottom, the fail, alarm 1, and alarm 2 relay terminal strips. They are three-position plug-in style terminal strips. The relay terminal strips are used to connect devices such as lights and horns that are controlled by the relay contacts. The relay contacts are rated at 115 VAC, 5 amps. The relay contacts may also be used to control higher rated relays.
switch below it. The magnetic switches are for use in non-intrusive calibration. They are actuated by bringing the magnetic wand close enough to them to actuate them. Although the magnetic switches have the same functions as the push button switches, it is not practical to use them for operations other than calibration because it is not possible to actuate two magnetic switches at once with only one magnetic wand.
Chapter 3: Installation & Startup Overview This chapter describes procedures to mount the M2A Transmitter in the monitoring environment and wire it to input power and devices. Mounting the M2A Transmitter 1. 2. Select a mounting site that is representative of the monitoring environment. Consider the following when you select the mounting site. • Select a site where the M2A is not likely to be bumped or disturbed.
4.59 5.00 3/4 NPT Conduit Hub 2.41 5.86 5.23 7.4 max 1.9 max .47 (2X) .30 (2X) 1.02 Figure 12: Outline & Mounting Dimensions, IR Combustible & CO2 4.59 5.00 3/4 NPT Conduit Hub 2.41 5.86 5.23 7.9 max 1 1/2-20 For Calibration Cup 1.02 .47 (2X) 2.6 max .
4.59 5.00 3/4 NPT Conduit Hub 2.41 5.86 5.23 6.5 max 1 1/2-20 For Calibration Cup 1.5 max .47 (2X) 1.02 .30 (2X) Figure 14: Outline & Mounting Dimensions, Replaceable Sensor, Non Explosion Proof, H2S, CO, and Oxygen 4.59 5.00 2.41 5.86 3/4 NPT Conduit Hub 5.23 8.4 max .47 (2X) .30 (2X) 3.2 max 1.
4.59 5.00 3/4 NPT Conduit Hub 2.41 5.86 5.23 10.4 max .47 (2X) 4.82 max .30 (2X) 1.
Wiring the M2A Transmitter WARNING: Always verify that the power source is OFF before making any wiring connections. 1. Remove the junction box cover. 2. Grasp the control PCB by its edges. 3. Gently pull until the control PCB is pulled away from the banana jacks. Take care not to pull too hard and damage the cable which connects the control and terminal PCBs. 4. Let the control PCB hang by the cable. The terminal strips are now visible on the terminal PCB.
• Oxygen Detector, Partial Pressure, Capillary Type, and CSA Capillary Type A B C R S 485 White C N C NO ALARM 2 + TOXIC + OXY Green C NC NO ALARM 1 S + PWR/SIG C N C NO FAIL The wiring for all the oxygen detectors is the same. White wire to terminal labeled OXY +, green wire to terminal labeled OXY -.
C NC NO F AIL C NC NO ALARM 1 - S + PWR/SIG A B C RS 485 White C NC NO ALARM 2 + T OXIC + OXY Green Figure 22: Capillary Type Replaceable Sensor Oxygen Detector Wiring • CSA type CO or H2S gas detector. B C RS 485 C NC NO ALARM 2 + TOXIC + OXY Black C NC NO ALARM 1 - S + PWR/SIG C NC NO FAIL Red wire to terminal labeled TOXIC +, black wire to terminal labeled TOXIC -.
• ESM-01 Toxic Detectors B C R S 485 NC NO F AIL C A See Chart C NC NO ALA RM 1 + T OXIC + OXY Black C NC NO ALARM 2 S + P W R/SIG The ESM-01 toxic detectors have one black wire and one color coded wire. Connect the color coded wire (see chart below) to the terminal labeled TOXIC + and the black wire to the terminal labeled TOXIC -. Wire Color Gas Type Brown AsH3 Yellow Cl2 Red Orange NH3 NO Green Blue PH3 SO2 Figure 25: ESM-01 Toxic Detector Wiring 6.
The number of cables or wires needed will depend on whether the M2A is wired to a gas monitoring controller or just to power, whether any relays are used, and whether the Modbus output is used. NOTE: If the M2A is being wired to a PLC or DCS device, see “Appendix B: PLC and DCS Device Wiring” on page 66, then continue with step 8.
See Figure 26 below for field wiring connections to the M2A. Alarm Device Power Alarm 1 Alarm Device Alarm 2 Alarm Device Typical Alarm Wiring Shown A See Modbus Wiring B C RS 485 R See Detector Wiring C NC NO FAIL (24 VDC) - W G LEL B 4 - 20 mA In (S) Fail Alarm Device C NC NO ALARM 1 S + PW R/SIG (24 VDC) + C NC NO ALARM 2 RKI Controller Terminals Figure 26: Wiring the M2A to a Controller and Alarm Devices 8. Re-install the control PCB (and ribbon cable if necessary).
NOTE: Allow the M2A’s detector to warm up for 15 minutes before you continue with the next section, “Adjusting the Fresh Air Reading.” Adjusting the Fresh Air Reading When the M2A is shipped from RKI Instruments, Inc., it is factory calibrated. If a full calibration is desired at startup, see “Calibration, Combustible Gas, CO2, and Toxic Versions” on page 42 or “Calibration, Oxygen Version” on page 45.
2. Press and release the UP/YES button to continue. The display will indicate the target gas and CAL Mode for a few seconds before showing FreshAir Adjust?. 3. Press and release the UP/YES button. ENTER will alternate with FreshAir on the top display line and the current gas reading will be on the bottom display line. 4. Press and release the ENTER button. The M2A will perform a zero operation and the display will indicate SPAN w/Cal Gas?. 5. Press and release the DOWN/NO button.
Chapter 4: Operation Overview This chapter describes the M2A in normal operation. This chapter also describes the M2A in alarm 1, alarm 2, and fail conditions and suggests responses to these conditions. Normal Operation Normal operation is defined as follows: • The start-up procedure is complete. • The M2A is not indicating an alarm 1, alarm 2, or fail condition. • The M2A is not in Calibration, Configuration, or Gas Type modes.
4 - 20 mA Signal Output Operation The output at the S terminal of the power/signal terminal strip is a 4 - 20 mA signal that corresponds to the detection range of the M2A. During normal operation, this signal tracks the gas concentration on the OLED display. There are several circumstances where the signal output will not track the display reading but will behave as follows: 27 • When the M2A is in its warm-up period, the signal output will be fixed at 3.5 mA (zero) for all gas types except oxygen.
Alarm Indications NOTE: The M2A includes alarm on and alarm off delay settings for alarm 1 and alarm 2. The alarm indications described in this section operate according to the factory set alarm settings. See Table 6 on page 32 for all the factory settings.
OLED display, and de-energizes the alarm 1 relay. NOTE: If the ENTER button is pressed while the M2A is in an alarm 1 condition, the A1 LED will flash but all other indications will remain unchanged. You cannot de-energize the alarm 1 relay until the gas reading falls below (above for oxygen) the alarm 1 setpoint. Alarm 2 Condition Alarm 2 Condition Indications When the gas reading reaches the alarm 2 setpoint, the M2A senses an alarm 2 condition.
Responding to a Fail Condition 1. Verify that the detector wiring is correctly and securely connected. 2. If the M2A has a replaceable plug-in sensor, verify that the replaceable plug-in sensor in the detector housing is properly installed. Low Power Alarm Low Power Alarm Indications The M2A senses a low power condition when the DC power source is 9.5 volts or less. WARNING: While in a low power condition, the M2A is not an active gas monitor.
Chapter 5: Configuration Mode Overview This chapter describes how to view and change M2A parameters using Configuration Mode. It is accessed using the program buttons. Configuration Mode includes a 5-minute time-out feature. If you do not press a control button for 5 minutes, the M2A automatically returns to normal operation. NOTE: If the M2A returns to normal operation because of a time-out, it enters a warm-up period just as it does when it is first turned on.
Table 6: Configuration Parameters Parameter (Factory Set Value) Description ALARM-1 (level) (See “M2A Specifications” on page 2) The gas reading at which the M2A initiates an alarm 1 condition. ALARM-1 (activation) (Decrease for oxygen M2A, Increase for all other types) Indicates if the alarm 1 circuit is activated by gas readings increasing (Increase) or decreasing (Decrease) to the ALARM-1 Level. ALARM-1 (relay action) (N. DE-EN) If set as N.
Table 6: Configuration Parameters (Continued) Parameter (Factory Set Value) Description ZeroSupp (0.0% of the detection range in terms of the detection units for carbon dioxide channel types, 0.5% oxygen for oxygen types, 2% of the detection range in terms of the detection units for all other types) The zero suppression feature helps prevent “jumpy” readings near the fresh air reading. For example, if the zero suppression setting for a combustible LEL detector is 2.
Chapter 6: Gas Type Mode Overview This chapter describes how to use Gas Type Mode to select the M2A’s gas type. The gas type determines the target gas and detection range. The combustible gas/CO2 and toxic/oxygen M2As have a different terminal PCB and run on different firmware. Your M2A will only have gas type choices available that it can support. Gas Type Mode includes a 5-minute time-out feature. If you do not press a button for 5 minutes, the M2A automatically returns to normal operation.
Table 7: Combustible Gas/CO2 Gas Types Gas Type Choices Detection Range CO2 0 - 2,000 ppm CO2 0 - 100% volume CO2 0 - 50.0% volume CO2 0 - 5.00% volume NH3 0 - 5.00% volume NH3 0 - 2.00% volume Table 8: Toxic/Oxygen Gas Types Gas Type Choices 35 Detection Range H2S 0 - 100 ppm CO 0 - 300 ppm OXYGEN 0 - 25.0% volume SIH4 0 - 15.0 ppm PH3 0 - 1.00 ppm O3 0 - 1.00 ppm NO 0 - 100 ppm HF 0 - 9.00 ppm HCN 0 - 15.0 ppm HCL 0 - 15.0 ppm H2SE 0 - 5.00 ppm GEH4 0 - 1.
NOTE: Consult factory for availability of detectors for toxic M2A types not listed in “M2A Specifications” on page 2. 4. When the desired target gas is on the display, press and release the ENTER button. The display will ask SAVE IT? YES/NO. 5. To discard the gas type change, press and release the DOWN/NO button. The display will ask DO OVER? YES/NO. Press the DOWN/NO button. The display will ask ABORT? YES/ NO. Press the UP/YES button.
Chapter 7: Maintenance Overview This chapter describes procedures for performing preventive maintenance, troubleshooting, calibrating the M2A, and replacing field replaceable parts. It includes separate procedures for calibrating the combustible gas/CO2/toxic and oxygen versions of the M2A. Preventive Maintenance This section describes a recommended preventive maintenance schedule to ensure the optimum performance of the M2A. It includes daily, monthly, quarterly, and biannual procedures.
NOTE: When applying gas to an NH3 ESM-01, the 0.25 LPM flowrate regulator must be used. All other M2As require a 0.5 LPM flowrate regulator. 5. Screw the calibration gas cylinder into (onto for an H2S cylinder) the fixed flow regulator. 6. Turn the regulator knob counterclockwise to open the regulator. 7. Allow calibration gas to flow for one minute. 8. Verify that the display reading is within ± 20% of the gas concentration.
Troubleshooting The troubleshooting guide describes symptoms, probable causes, and recommended action for problems you may encounter with the M2A. NOTE: This troubleshooting guide describes M2A problems only. If the M2A is connected to a controller, see the controller operator’s manual for problems you may encounter with the controller.
Table 9:Troubleshooting the Combustible Gas Detector (Continued) Condition Fail Condition Symptom(s) • • M2A indicates a fail condition. Controller indicates a fail condition Probable Causes • • • • • Slow or No Response/ Difficult or Unable to Calibrate • • • M2A responds slowly or does not respond to response test. Unable to successfully set the fresh air or span (zero for oxygen) reading during calibration. M2A requires frequent calibration.
Calibration Frequency Some M2As have IR (infrared) type detectors, such as an M2A for CO2 or an LEL M2A with an IR detector. Most of the M2As do not have an IR detector. For example, an H2S M2A has an electrochemical detector and some of the combustible M2As use catalytic detectors. The M2As that use IR detectors typically need less frequent calibration as is discussed below. See Table 1, “M2A Specifications,” on page 2 to see which M2As are IR versions.
Calibration, Combustible Gas, CO2, and Toxic Versions This section describes how to calibrate the combustible gas, CO2, and toxic gas versions of the M2A. It includes procedures to prepare for calibration, enter Calibration Mode, adjust the fresh air (zero) setting, adjust the span setting, and return to normal operation. See the next section, “Calibration, Oxygen Version” for instructions to calibrate an oxygen M2A. WARNING: The M2A is not an active gas monitoring device during the calibration procedure.
Non-Intrusive Calibration If the M2A is installed in a classified area and non-intrusive calibration is required, follow the instructions below, but do not remove the junction box cover. Use the magnetic wand accessory to actuate the magnetic switches instead of pushing the control switch buttons.
Adjusting the Span Setting 1. If you want to continue with adjusting the span setting, press and release the UP/YES button. APPLY will alternate with SPAN Gas on the top display line and the current gas reading will be on the bottom display line. If you want to skip adjusting the span reading, press and release the DOWN/NO button. The display will indicate Leaving Cal Mode and the M2A will return to normal operation. 2.
Calibration, Oxygen Version This section describes how to calibrate the oxygen version of the M2A. It includes procedures to prepare for calibration, enter Calibration Mode, set the fresh air (span) reading, set the zero reading, and return to normal operation. WARNING: The M2A is not an active gas monitoring device during the calibration procedure. The 4-20 mA output signal will “freeze” at 17.4 mA and all relays will remain in their non-alarm state while the M2A is in Calibration Mode.
reading at the highest response and the M2A will continue to display this reading and retain it in its memory until the fresh air adjustment procedure is completed. When calibration gas is applied to the M2A during a zero adjustment, the M2A will freeze the display reading at the lowest response to the calibration gas. The calibration gas can then be removed and the M2A will continue to display this reading and retain it in its memory until the zero adjustment procedure is completed.
5. Turn the regulator knob clockwise to close the regulator. 6. Unscrew the nitrogen cylinder from the fixed flow regulator and unscrew the calibration cup from the detector. The M2A will continue to display the minimum gas response on the display and retain the response level in its memory. 7. Adjust the oxygen reading up or down to match the 100% nitrogen cylinder oxygen concentration of 0 by using the UP/YES and DOWN/NO buttons. NOTE: 8. Press and release the ENTER button.
coded leads as you remove them. 8. Unscrew the detector from the junction box. 9. Guide the replacement detector leads through the bottom conduit hub of the junction box, then screw the mounting threads of the detector into the conduit hub. 10.
rubber boot and spacer from the old sensor. 5. If you are replacing a CO sensor, install the rubber boot and charcoal filter onto the new sensor’s face. If you are replacing the 65-2423RK-05 explosion-proof H2S detector’s sensor, install the rubber boot and spacer on the new sensor’s face. 6. Carefully match the replacement sensor’s male pins with the 4-socket pattern in the top section and plug it in. 7. Make sure the cap gasket is in place and screw the detector cap back onto the housing body. 8.
NOTE: 7. Allow the replacement sensor to warm up for 15 minutes before you continue with the next step. Calibrate the detector as described in “Calibration, Combustible Gas, CO2, and Toxic Versions” on page 42. Replacing an ESM-01 Plug-in Sensor 1. Turn off or disconnect power to the M2A. 2. Unscrew the detector cap from the detector housing body. Take care not to lose the cap gasket. If the splashguard begins to unscrew from the detector cap, make sure to remove the detector cap also.
Chapter 8: RS-485 Modbus Output Overview This chapter describes the M2A’s RS-485 Modbus output and how to configure the M2A to make use of it. It also discusses how to wire the M2A into a Modbus system. The M2A provides an RS-485 serial communications interface. It is a Modbus Slave Device, supporting 2-wire RS-485 Modbus RTU serial communications. Wiring the M2A in a Modbus System The M2A is a 2-wire Modbus RTU device.
Recommended Modbus Wiring The recommended Modbus wiring for the M2A is illustrated in Figure 27 below. In this configuration, 5 wires are used for wiring the M2A into a Modbus system. Figure 27 also illustrates typical alarm device wiring. The ground jumper must be removed in this wiring configuration.
Adding an M2A to an Existing M2 Modbus Installation with Alternate Wiring An M2A can be wired into an existing M2 Modbus system. The shape of the terminal PCB will be different but the wiring connections are identical and the ground jumper on the M2A must still remain installed. Termination Jumper The M2A includes a 2-pin termination header (see Figure 9) that is used when the M2A is used in a Modbus system. Every M2A is supplied with a termination jumper (a jumper block) installed onto this header.
ID = 128 ID = 1 M2A Termination Jumper Installed M2A Termination Jumper Installed Modbus Master RS-485 RS-485 M2A Termination Jumper Not Installed M2A Termination Jumper Not Installed M2A Termination Jumper Not Installed M2A Termination Jumper Not Installed ID = 2 ID = 3 ID = 4 ID = 127 Up to 128 M2As can be connected without a repeater Figure 30: Multiple M2As in a Two Branch Configuration Using the M2A in a 4-wire Modbus System Although the M2A is a 2-wire Modbus RTU device, it can be used
for 5 seconds to enter Modbus Mode. Release the buttons when the following screen appears. Set Up Modbus? 2. To exit Modbus Mode, press and release the DOWN/NO button. The M2A will return to normal operation. To continue in Modbus Mode, press and release the UP/YES button. The current ENABLED/ DISABLED setting will appear. 3. If you want to change the currently displayed parameter, use the UP/YES and DOWN/NO buttons to adjust it to the desired setting, then press ENTER to continue to the next parameter.
Table 11: Configuration Parameters Modbus Mode Parameter Available Settings & Description Enabled/Disabled Can be set to ENABLED or DISABLED (factory setting). Enables or disables the Modbus output. Slave ID The Slave ID can be set to values from 1 (factory setting) to 247. The M2A will only receive messages from the Master which are addressed to this Slave ID (except for broadcast messages which are received by all slaves).
Supported Modbus Functions The M2A supports Function Code 03: Read Holding Registers and Function Code 16: Write Registers. Function Code 03: Read Holding Registers There are a total of 40 registers available to be read via this Function Code. Registers 1 - 2 The format (bit & field assignments) for registers 1 - 2 is shown below in Table 12 - Table 13.
Table 13: Register 2, Operating State, Alarms & Relays Bit & Field Assignments (Continued) Bit(s) Value [7:6] Alarm 2 Status 0 = No Alarm 1 = Unacknowledged Alarm 2 = Acknowledged Alarm 3 = Unused Code [5:4] Alarm 1 Status 0 = No Alarm 1 = Unacknowledged Alarm 2 = Acknowledged Alarm 3 = Unused Code [3] Overscale Status 0 = Not Overscale 1 = Overscale [2] Fail Relay Status 0 = Not Energized 1 = Energized [1] Alarm 2 Relay Status 0 = Not Energized 1 = Energized [0] Alarm 1 Relay Status 0 = Not E
Register 23 Register 23 is the alarm 1 trigger. 0=Decreasing 1=Increasing Register 24 Register 24 is the alarm 1 normal relay state. 0=Normally De-Energized 1=Normally Energized Register 25 Register 25 is the alarm 1 relay reset. 0=Latching 1=Self-Resetting Register 26 Register 26 is the alarm 1 ON delay. Integer values are in seconds. Register 27 Register 27 is the alarm 1 OFF delay. Integer values are in seconds. Register 28 Register 28 is the alarm 2 trigger.
Register 34 Register 34 is noise filter. Integer values in seconds. 0-60 in 5 second increments. Register 35 Register 35 is calibration timeout in minutes (5, 10, 15, 20, 25, or 30). Register 36 Register 36 is calibration month (upper byte) and day (lower byte). This is zero based (e.g. January=0 and the 1st=0). Register 37 Register 37 is the calibration year. Register 38 Register 38 is the calibration outcome.
Function Code 16: Write Registers There are 21 registers in Function Code 16 that can be used to write to the M2A. This manual only describes Register 16 because it can be used to reset an alarm condition. For a complete description of Function Code 16, request Appendix C from RKI Instruments, Inc. Register 16 Register 16 performs the same function as the ENTER button on the M2A. It is useful for remotely silencing alarms. With the M2A in an alarm condition, bit [0] can be used to silence it.
Table 15: Parts List Part Number Description 61-0191RK-10 CO2 detector, IR type, 0 - 100% volume 61-0192RK-CH4 CH4 detector, IR type, 0 - 100% volume 61-0198RK-02 CO2 detector, IR type, replaceable sensor, 0 - 5000 ppm 61-0198RK-03 CO2 detector, IR type, replaceable sensor, 0 - 5% volume 61-0198RK-05 CO2 detector, IR type, replaceable sensor, 0 - 50.
Table 15: Parts List Part Number 63 Description 81-0013RK-05 Calibration cylinder, 50% volume methane in nitrogen, 58 liter steel 81-0064RK-01 Calibration cylinder, CO, 50 ppm in air, 34 liter steel 81-0064RK-03 Calibration cylinder, CO, 50 ppm in air, 103 liter steel 81-0070RK-01 Calibration cylinder, CO2, 2,000 ppm in nitrogen, 34 liter steel 81-0070RK-03 Calibration cylinder, CO2, 2,000 ppm in nitrogen, 103 liter steel 81-0072RK-01 Calibration cylinder, CO2, 2.
Table 15: Parts List Part Number Description 81-1117RK Calibration cup, for catalytic LEL, CO, H2S, and oxygen detectors 81-1138RK Calibration cup, general (SO2), for ESM-01, use 0.5 LPM flow 81-1138RK-CL2 Calibration cup, for ESM-01 Cl2, use 0.5 LPM flow 81-1138RK-NH3 Calibration cup, for ESM-01 NH3, use 0.
Appendix A: Control Button Quick Reference Guide The M2A’s control buttons allow access to operational modes, resetting of alarms, and display of the Information Screen. Table 16 shows which button combinations perform these functions and which parameters are available for adjustment while in the operational modes. While in these modes, display prompts showing a “?” require you to respond by pressing either the UP/YES (for yes) or DOWN/NO (for no) button.
Appendix B: PLC and DCS Device Wiring The M2A can be wired to a PLC or DCS device if desired. 1. Guide multi conductor shielded cable or cables or wires in conduit through the top conduit hub of the junction box. The number of cables or wires needed will depend on whether any relays are used and whether the Modbus output is used.
See Figure 31 below for field wiring connections to the M2A.
Appendix C: Function Code 16 Registers The M2A supports Function Code 16 that allows writing to the M2A. There are 21 registers in this Function Code. Register 1 Register 1 is the alarm 1 set point. Value must be an integer. Any decimals are omitted. Register 2 Register 2 is the alarm 1 trigger. 0=Decreasing 1=Increasing Register 3 Register 3 is the alarm 1 relay state. 0=Normally De-Energized 1=Normally Energized Register 4 Register 4 is the alarm 1 relay reset.
Register 10 Register 10 is the alarm 2 relay reset. 0=Latching 1=Self-Resetting Register 11 Register 11 is the alarm 2 ON delay. Integer value is in seconds. Register 12 Register 12 is the alarm 2 OFF delay. Integer value is in seconds. Register 13 Register 13 is the zero suppression. Toxics and LEL: 0%-6% Full Scale Oxygen: 0%-0.7% Oxygen Value must be an integer. Any decimals are omitted. Register 14 Register 14 is the noise filter. Integer value is in seconds (0-60 in 5 second increments).
Register 20 Register 20 is the AutoZero Disable. 0=AutoZero Enabled 1=AutoZero Disabled Register 21 Register 21 is the Remote Configuration Register.
