4-20 ma Output Board Dual Channel

Transcription

1 Honeywell Process Solutions 420 ma Output Board Dual Channel User Manual October 2010 V 2.12 Honeywell

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3 Table of Contents Description...5 Principal of Operation...5 Specifications...5 Power Requirements...6 Software Installation...6 Programming...7 Troubleshooting...9 Test Cable...10 Field Wiring...11 Field Installation of 420 ma Board into Mini/MiniAT...13 Field Installation of 420 ma Board into MiniMax

4 Revision List 2.11 Modified: Replaced Mercury logo s and type style May Honeywell update October

5 Description Mercury Instruments 420 ma output board (p/n ) interfaces with the ECAT, MiniAT, Mini, Mini Max and the ER. The board provides two isolated 420 milliamp (analog) current loops, which are individually settable, to track the userselected item values. Most item values produced by a Mercury electronic instruments can be represented by a 420 signal. Some of the more common items requested to be represented as 420 signals are: Average Flow Rate (ECAT, MiniMax and MiniAT*) Instantaneous Flow Rate (ECAT, MiniMax and MiniAT*) Dial Rate (ECAT, MiniMax and MiniAT*) Gas Pressure (all instruments) Gas Temperature (all instruments) Case Temperature (all instruments) Battery Voltage (all instruments) Incremental Corrected Volume (ECAT, MiniMax and MiniAT) * Denotes best instrument for this choice since its firmware was modified for this purpose Principal of Operation The 420 ma output board is a peripheral device designed specifically for use with Mercury Instruments ECAT, MiniMax, MiniAT, Mini and ER. The board contains a microcontroller which requires limited programming by the user. An easytouse configuration program allows the user to define the following parameters: Instrument Type (ECAT, MiniMax, MiniAT, Mini or ER) Instrument Baud Rate (1200, 2400, 9600 or 19200) Instrument Access Code Interrogation Interval (in seconds) Delay (Holdoff Interval)) after failed serial access (in seconds) Item Code Numbers to interrogate (000 to 999) Value that is to represent 4 ma (usually 0) Value that is to represent 20 ma (user discretion) All configuration information is stored in E 2 PROM to prevent loss of data in case of power failure. NOTE: When entering nonzero values for the 4mA and 20 ma parameters, two decimal positions are usually required, Ex instead of 100. While in operation, the 420 ma output board interrogates the instrument via the RS232 port on a periodic basis and reads the values of the two selected items. If the instrument serial port is busy, e.g. modem or laptop access etc., the 420 board waits the Holdoff Interval before attempting the next interrogation. After a successful link to the instrument, the two item values are scaled as a percentage of the 4mA and 20 ma parameters stored during configuration. The upper and lower parameters are configured separately for each loop. The scaled values are then converted to milliamp signals for output to two independent, optocoupled looppowered drivers. Specifications Designed for a Class 1, Div 2 environment Operating Temperature 40F to 150F (40C to 65.5C) Accuracy of the 420mA signal / 1% Board Size: 21/2 x 3 5

6 Loop1 Output Programming Jumper Loop2 Output RSIN (from instrument) RSOUT (to case connector) 24 VDC connection (to external power supply) Figure milliamp output PC board Power Requirements 420 ma Board: 24VDC 10% 50 ma (or greater) from external power supply 420 ma Outputs: Are looppowered and require a minimum of 9 volts across their and terminals under any load condition. Loop outputs and 24 vdc input are isolated from each other and from the RS232 circuitry to 1000 vrms. Note: Due to the high number of Serial accesses placing a heavy burden on the instrument battery pack, the Mercury Instrument device being interrogated by the 420mA board must be line powered. Use Mercury Instruments DCPS part # for instrument power. The DCPS is an AC to DC power converter to supply 9 volts to most Mercury Instruments electronic products. It includes a DC power pack, voltage regulator (with provisions for battery backup) and a surge suppressor. Software Installation The 420 milliamp board programming software is usually distributed on a single CD. To install the software to a PC, simply copy all files from the CD to a directory created on the PC. It is suggested that the directory be named so that the path is easy to remember (such as C:\Mercury\420). A shortcut to the 4 20 program can be created on the Windows Desktop by rightclicking the mouse while on PR420.exe file, select; Send To Desktop (new, shortcut). 6

7 Programming the 420 Milliamp Output Board: The 420 milliamp board may be programmed on the bench or in an instrument. When programming the 420 board on a bench, connect programming cable (p/n ) from RSOUT on the back of the 420 board (see Figure 1) to a COM1 port on a PC. The programming cable can be supplied with the 420 programming software. This same cable may also be used for programming or testing when the board is installed in an instrument, but the board may need to be loosened from its mounting. Prior to programming the 420 board, be sure to unplug the internal serial interface cable from the RSIN connector (white) on the 420 board, then position the RUN/PGM jumper to PGM. For a board already mounted in an instrument, it may be more convenient to connect to the board via the instrument s external serial port using a standard Mercury I/O cable (p/n ). However, two additional steps are required for this method. A null modem (or reversing cable of pins 2&3) such as Mercury Modem Configuration Cable (p/n ) must be connected between the PC and the I/O serial cable (401629). Secondly, the internal serial cable must be temporarily unplugged from the RSIN connector (white) on the 4 20 board, then position the RUN/PGM jumper to PGM. PR420 Program Instructions The PR420 program provides a Windows interface for programming the 420 board. Prior to programming, make sure the RUM/PGM jumper is in the PGM position, the board is connected to COM1 port on a PC with the proper cable mentioned above and temporarily unplug the internal serial cable from the RS IN connector (white) on the 420 board. Next, make the 11 selections required for 420 board setup. (Watch the status bar at the bottom of the window for descriptions and limits for each parameter. Decimal positions must be entered where required. 1. Select the instrument type 2. Select the baud rate for the particular instrument (19200 maximum) 3. Enter the instrument s serial access code (33333 is the default). 4. Enter the number of seconds desired between serial links 5. Enter the number of seconds to holdoff after other serial activity 6. Enter the item number for Loop 1 (must be 3 digits, i.e., 008 ) 7. Enter the Loop 1 value that corresponds to 4 milliamps 8. Enter the Loop 1 value that corresponds to 20 milliamps 9. Enter the item number for Loop 2 (must be 3 digits, i.e., 225 ) 10. Enter the Loop 2 value that corresponds to 4 milliamps 11. Enter the Loop 2 value that corresponds to 20 milliamps Click on Program. If all entries are within limits and all serial connections are correct, a blue progress bar will appear. The progress bar will scroll quickly if no problems are encountered. If the progress bar stops after about 4 or 5 blocks, check your cabling, baud rate setting and jumper position. Following the successful programming of the 420 board, remove 24 volt power from the board. Place the RUN/PGM jumper in the RUN position. Plug the serial cable back into the RSIN connector (white) on the 420 board. Restore 24 volt power to the board. 7

8 NOTE: It s recommended that the Serial Log Trigger (Item 238: REPORT TRIGGER 4 in the MiniAT and ECAT, or Item 602: SERIAL TRIGGER ENABLE in the ER) be configured as INACTIVE. Failure to do so will result in excessive Serial Log Triggers in audit trail memory which will severely limit the number days of Time logs. Programming Example #1: Below is an example of how the information would be entered if the user wanted to output a 420 signal for pressure (0100) and temperature (40 to 170) from a MiniAT every 30 seconds. In this example, Item 088 (PRESSURE DISPLAY RESOLUTION) is set to the default of two decimal places. Since the resolution of temperature is always two decimal places, both need to be accounted for in the Loop settings. Going Further Suppose the same setup is desired for an ER. This can be easily accomplished by changing the above programming parameters to the following: Instrument to ER, Loop1 Item No. to 500, and Loop 2 Item No. to 502. Baud Rate and Access Code may also need to be changed to match that of the instrument. The PRES SURE DISPLAY RESOLUTION at Item 552 must be taken into consideration by using the appropriate number of decimal places when entering the 4 ma and 20 ma values. 8

9 Programming Example #2 In this example, the desired output is INSTANTANEOUS FLOW RATE, Item 209 for Loop 1, and GAS PRESSURE, Item 008 for Loop 2. Suppose that the desired output for Loop 1 is 0 to 10 MCF/hour and for Loop 2, the output is 0 to 600 PSI. In this case Item 090, CORRECTED VOLUME UNIT CODE must be set to MCF or CFx1000. The completed setup screen would appear as below. Troubleshooting Likely causes of programming failure are: board not powered by an external 24 volt power supply 2. RUN/PGM jumper in the wrong position 3. Incorrect or reversed serial (programming) cable 4. Internal serial cable attached from the 420 Board RSIN to Instrument main board (this cable must be unplugged during programming) 5. Improper COM port connection to PC (COM1 or COM2 only) 9

10 420 Milliamp Test Cable A test cable (p/n ) is available for the 420mA output board. This cable allows for quick testing of the 420mA board programming on the bench. A 24 VDC power source is required to use the test cable. The cable assembly consists of a plug for 420 board, connections for a 24VDC power supply, and test jacks to check the loop values. The test jacks consist of a positive and negative lead for each loop. The test is performed by making a connection with the 420mA board through the screw terminals. While the jumper JP1 is in the RUN position, plug the spade connectors to a 24VDC power supply. The 420 loops can be checked by measuring the voltage at the test jacks. A voltage of 15V corresponds to 420mA. e.g. 1V=4mA, 5V=20mA Connection Pins to 420 Test Jacks Figure 2 Test Cable Assembly 10

11 Field Wiring: Refer to the drawing below and on the next page for wiring to the field device (RTU) that will receive the 4 20 signal. Use shielded paired or multiconductor cable, 24 gauge or larger. It is acceptable for all field wires to the board to be within a single shield. The loop resistance, including cabling and receiver, must maintain a minimum of 9 volts across the board s loop terminals (about 650 ohms total). The voltage at the board s 24 VDC terminals under all load conditions must be 24 VDC 10% 2%. 420 ma loops are isolated from each other, from instrument, from 24VDC power supply, and from ground. The 24 DC supply is similarly isolated. 420 ma outputs are loop powered and require a minimum of 9 volts across their and terminals under any load conditions. Wiring Diagram, RTU with Internally Powered Loop Receivers 24 VDC Regulated 24 VDC Supply 10% 2% 4to20 ma PC Board Loop 2 4to20 ma Receiver Loop 1 4to20 ma Receiver Figure 3 Field Wiring Diagram 11

12 Wiring Diagram RTU with Separately Powered Loop Receivers RTU Loop Receivers referenced to Power Supply Common (Preferred) 24 VDC Regulated 24 VDC Supply 10% 2% 4to20 ma PC Board Loop 2 4to20 ma Receiver Loop 1 4to20 ma Receiver 12

13 Field Installation of the 420 ma Output Board into Mercor Mini & MiniAT Reference: ma Board Kit Mercor Mini/MiniAT& Wiring Drawing NOTE: Follow the procedure appropriate for the configuration of your instrument. Mini/MiniAT Without Modem or Permanent Serial Device (Ref. Figure 1): 1. Place the corrector in Shutdown condition as described in the instruction manual (MiniLink Software User s Guide, section 6.3 or MiniATLink Software User s Guide, section 5.2). 2. Remove the left UMB nut and ground wire (if attached to the UMB stud). 3. Install the bracket assembly provided on the UMB stud with the lip facing the front of the case, flat side down. Install ground wire (if removed in step 2), lock washer, and nut. 4. Install the 420 ma board on the bracket and tighten screws. 5. Disconnect the serial cable from main board connector J6 (left edge) and connect it to RS OUT on the back of the 420 ma board. 6. Connect the white plug of cable (provided) to RS IN on the 420 ma board. Connect the other end to main board connector J6, oriented with the white wire at the top and the clear shield wire at the bottom. 7. Connect 420 ma outputs per the output wiring detail on wiring drawing Verify that no wires interfere with door closure. 9. Bring the corrector out of Shutdown condition and back into Corrector Mode using the procedure found in the instruction manual. Verify that the instrument is operating correctly. This completes the installation procedure. Figure ma Board 13

14 MiniAT With Modem or Permanent Serial Device(Ref. Figure 2): Configuration 1 (MiniAT only) No SCIB Installed: Perform steps 1 through 6 above. 7. Connect 3conductor cable (provided) to main board connector TB2 (red to Tx, white to Rx, black to COM). Connect the other end to TB1 on the Mercury modem or J3 on the Messenger/ Power Smart modem (red to Rx, white to Tx, black to GND or COM). 8. Verify that no wires interfere with door closure. 9. Bring the corrector out of Shutdown condition and back into Corrector Mode using the procedure found in the instruction manual. Verify that the instrument is operating correctly. This completes the installation procedure. Figure ma Board w/scib Configuration 2 SCIB Installed (Ref. Figure 2): 1. Place the corrector in Shutdown condition as described in the instruction manual (MiniLink Software User s Guide, section 6.3 or MiniATLink Software User s Guide, section 5.2). 2. Replace the (2) SCI board mounting screws with the (2) standoffs provided. Tighten them against the SCI board. 3. Install the 420 ma board on the standoffs using the (2) screws removed in step Unplug the SCI board cable from main board connector J6 and plug it into the RS OUT connector on the back of the 420 ma board, oriented with the white wire at the top and the clear shield wire at the bottom. 5. Connect the white plug of cable (provided) to RS IN on the 420 ma board. Connect the other end to main board connector J6, oriented with the white wire at the top and the clear shield wire at the bottom. 6. Connect 420 ma outputs per the output wiring detail on wiring drawing Verify that no wires interfere with door closure. 8. Bring the corrector out of Shutdown condition and back into Corrector Mode using the procedure found in the instruction manual. Verify that the instrument is operating correctly. This completes the installation procedure. 14

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16 Find Out More: To learn more about Mercury Instruments products, contact your Honeywell Process Solutions representative, visit or call Automation and Control Solutions Honeywell Process Solutions 3940 Virginia Ave. Cincinnati, OH MNL4201 October Honeywell