Example ladder logic program – Rockwell Automation 150 USE MN/SMC DIALOG + CONTROLLER User Manual

Page 142

Serial Communications

8-33

Note: There is no required value for the words identified as “Data

Place Holder”.

Example Ladder Logic Program:

Rung 0: The 1747-SDN scanner module will map output data from its scanner output table (MO) and discrete outputs to each node only when it’s in the
“run mode.” This is accomplished by setting bit 0 of the 1747-SDN’s command word (word 0).

Rung 1: When the START command is initiated at the RSView station the SLC processor sets the output bit mapped to the SMC Dialog Plus controller’s
logic control word start bit. The branch provides a logic “latched” circuit which exerts the START command until input from the SMC Dialog Plus
controller’s status word indicates that it has received the command and has responded appropriately. The SMC Dialog Plus controller will start if no
STOP command is being issued by the SLC or any other control device.

Rung 2: When the STOP command is initiated at the RSView station, the SLC processor sets the output bit mapped to the SMC Dialog Plus controller’s
logic control word stop bit. The branch provides a logic “latched” circuit which exerts the STOP command until input from the SMC Dialog Plus
controller’s status word indicates that it has received the command and has responded appropriately.

1747-SDN
Enable
Bit

SMC
START
Command

SMC
STOP
Command

SMC
START
Command

SMC
STOP
Command

SMC
Running
Bit

Start CMD
From
RSVIEW

Stop CMD
From
RSVIEW

: 1

: 1.7

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