AB SLC 5/04 Chanel 0 Node DF1 Half Duplex Master


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I have setup a AB SLC 5/04 as Master trough Ch 0 DF1 Half Duplex Master and another AB SLC 5/04 as Slave trough CH 0 DF1 Half Duplex Slave. I can read and write data to slave AB SLC 5/04 but Why I can't see active node from Table S2:67 - S2:82 at SLC 5/04. There are anything else need to set. Thanks Suradi System Engineer Indonesia email : [email protected]

Alan Rimmington

DF1 is a point to point protocol and therefore would not give an active node indication. If the reason for wanting to read "active node" is to confirm that communications are healthy you would be better implementing a watchdog system between the PLCs.

amora fibrianto

I think AB SLC500 DF-1 Half Duplex has a several mode to talk to it's slave.....to name a few..... 1. Standard Communication 2. Message based Communication. In standard communication mode, you can see active station in your Table S2:67 - S2:82... But in message based communication, you can't see the active node. Please refer to AB Scada Application Guide for more detailed on setting up the port. Which one is yours ?? Regards, Amora Fibrianto Engineering Dept. Somit Automation http://www.somit.co.id [email protected]
Suradi, The bits in Status words S2:67 through S2:82 which represent the 255 possible DF1 Half-Duplex slave addresses are only set if the slave is responding to poll requests from the DF1 Master processor. There are four settings for Polling Mode of the master SLC-5/04; Message-Based (allow slaves to initiate) Message-Based (do not allow slaves to initiate) Standard (single message per scan) Standard (multiple messages per scan) The Channel 0 Active Node Table only updates when one of the "Standard" polling modes is selected. The Channel 0 Active Node Table also works for Nodes 0-31 when that channel is configured for DH-485. Regards, Ken Roach Rockwell Automation / Seattle [email protected]