Flowserve MX/QX Profibus DP/PA Field Unit - Manual (Page 50)

PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
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3.6 Discrete Output (DO) Function Block
The Discrete Output (DO) block accepts a “command” value from the network user. This command
value flows through the DO block algorithm. The DO block then provides this “command” data to the
transducer block, and the actuator takes some action based on this “command.” The function block
also provides readback data allowing the network user to configure closed-loop control processes.
The DO block supports mode control and simulation.
There are two DO blocks in the MX/QX actuator device. Each DO function block can be assigned to
one of the following channels:
Channel Channel Name Description
354 DO_POSITION_CHAN Command Stop/Open/Close
355 DO_ESD_CHAN Command Emergency Shutdown
356 DO_RELAY_CHAN Command Energize Relays
NOTE: Please note that the quality status bit must be set to “good”, prior to or while sending
command data. This is required in order for the actuator to respond to DO block commands. See
“Status Bit Definitions” section on page 70 for coding of quality status bits.
Figure 3.10 – Summary of the Parameters of the Discrete Output Function Block
DO
Function
Block
SP_D
READBACK_D
OUT_D
Standard Configuration Parameters
(Acyclic Data)
Example: CHANNEL
INVERT
Process Parameter
(Cyclic Data)
}