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Author Topic: Using the Modbus protocol how do I read if a DM is in run mode?  (Read 7093 times)

Henryp

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Using the Modbus protocol how do I read if a DM is in run mode?
« on: August 28, 2017, 06:14:04 PM »
I have a rung of code looking to see if DST10 is equal to 3 which turns on a Modbus output coil. However when I place the DM in program mode the Modbus coil remains on. I assume it is because the ladder is no longer running. So how do I read if a DM is in run mode?

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BobO

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Re: Using the Modbus protocol how do I read if a DM is in run mode?
« Reply #1 on: August 28, 2017, 06:40:00 PM »
You can use the $LastScan block to execute code as the PLC is going to program mode.
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Controls Guy

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Re: Using the Modbus protocol how do I read if a DM is in run mode?
« Reply #2 on: August 28, 2017, 07:27:37 PM »
You can also look at a clock bit and see if it keeps toggling.
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