Flowserve MX-100 Field Unit - Manual (Page 22)

MX/DDC-100 Field Unit Installation and Maintenance FCD LMENIM2329-01 – 03/11
22
Message Breakdown
Query Response
46 Slave (Field Unit) Address 46 Slave (Field Unit) Address
04 Function 04 Function
00 Starting Address Hi 08 Byte Count
04 Starting Address Lo FF Data Hi (Register 40005)
00 No. of Points Hi FF 1 Data Lo (Register 40005)
04 No. of Points Lo FF Data Hi (Register 40006)
BF7F Error Check (CRC) FF 2 Data Lo (Register 40006)
00 Data Hi (Register 40007)
2B 3 Data Lo (Register 40007)
00 Data Hi (Register 40008)
1E
4
Data Lo (Register 40008)
DBA8 Error Check (CRC)
Note 1: FFFFh equals 65535 Decimal (actuator Analog Input 4 value).
Note 2: FFFFh equals 65535 Decimal (actuator Analog Input 3 value).
Note 3: 002Bh equals 43 Decimal (actuator Analog Input 2 value).
Note 4: 001Eh equals 30 Decimal (actuator Analog Input 1 in percent format).
2.3.7 Modbus Function Code 05 (Force Single Coil)
This function code is used to force a single coil in the DDC-100 Field Unit. Forcing the individual coil either ON (1) or
OFF (0) will energize or de-energize a coil (digital output) in the field unit. Coil 1 in the field unit closes the actuator
and Coil 2 opens the actuator. If the actuator is opening or closing, changing the status of coil 1 or 2 from a value of
1 to 0 will stop the actuator (the coil will automatically be set to zero when the actuator reaches the full open or full
close position).
Available digital outputs for DDC-100 Field Units are listed in Table 2.5. Force-coil commands should be issued
only once for the desired field unit control. Repeated issuance of an acknowledged command will degrade network
performance.
NOTE: See Bulletin LMAIM1329, Accutronix Installation and Operation for MX-DDC Field Unit to configure AS and
AR Relays for DDC control.
Table 2.5 – DDC-100 coil assignments, Modbus 05 command usage for digital outputs
Coil Number Bit Number Function
1 00 Close/Stop
2 01 Open/Stop
3 02 S1 or R1 (Opt) Latched
4 03 S2 or R2 (Opt) Latched
5 04 R3 (Opt) Latched
6 05 R4 (Opt) Latched
7 06 R5 (Opt) Latched
8 07 R6 (Opt) Latched
9 08 R7 (Opt) Latched
10 09 R8 (Opt) Latched
The normal response to the (05) command is an echo of the command.