Flowserve MX-100 Field Unit - Manual (Page 24)

MX/DDC-100 Field Unit Installation and Maintenance FCD LMENIM2329-01 – 03/11
24
Table 2.6 – Modbus 06 command and field unit holding register 40001
Host Commands to Field Unit Register 1 Value (Decimal) Function
Null Command 0 No action
Open 256 Open actuator
Stop 512 Stop actuator
Close 768 Close actuator
Reset Field Unit 1024 Reset processor
Start Network ESD 1280 ESD initiate
Stop Network ESD 1536 ESD terminate
Engage Relay #1 2304 S1 or R1 (opt)
Engage Relay #2 2560 S2 or R2 (opt)
Engage Relay #3 2816 R3 (opt)
Engage Relay #4 3072 R4 (opt)
Engage Relay #5 3328 R5 (opt)
Engage Relay #6 3584 R6 (opt)
Engage Relay #7 3840 R7 (opt)
Disengage Relay #1 4352 S1 or R1 (opt)
Disengage Relay #2 4608 S2 or R2 (opt)
Disengage Relay #3 4864 R3 (opt)
Disengage Relay #4 5120 R4 (opt)
Disengage Relay #5 5376 R5 (opt)
Disengage Relay #6 5632 R6 (opt)
Disengage Relay #7 5888 R7 (opt)
Move-To (Enable) 1 6656 Initiates “move-to”
Engage Relay #8 6912 R8 (opt)
Disengage Relay #8 7168 R8 (opt)
Note 1: This is a two-step command. A valid value must be written to Register 2 before issuing this command.
(See Note 1 of Table 2.2.)
Other registers may also be preset to control or change other functions but care must always be taken to properly
change these values. An improper value written to a register can cause undesirable actions from the DDC-100 Field
Unit.
NOTE: Null Command–The field unit takes no action when this command is received. This command is typically used
by a Host to reset the Host output register when required.
Example of Field Unit Command
Write the command to open an actuator (actuator open) to field unit number 179. This corresponds to writing the
value 256 into field unit register 40001.
Query: B306000001009388
Response: B306000001009388
Message Breakdown
Query Response
B3 Slave (Field Unit) Address B3
Slave (Field Unit)
Address
06 Function 06 Function
00 Register Address Hi 00 Register Address Hi
00 1 Register Address Lo 00 Register Address Lo
01 Force Data Hi 01 Preset Data Hi
00 2 Force Data Lo 00 Preset Data Lo
9388 Error Check (CRC) 9388 Error Check (CRC)
Note 1: 0000h equals Register Address 40001 (field unit register 1, command register).
Note 2: 0100h requests the register to be preset with 256 Decimal (engage open contactor).