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st-one-io / node-red-contrib-cip-ethernet-ip

A Node-RED node to interact with Allen Bradley / Rockwell PLCs
GNU General Public License v3.0
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NULL values on PLC reconnect #5

Closed jpillman closed 5 years ago

jpillman commented 5 years ago

I'm using your module to communicate with a CompactLogix PLC and am using the "All tags" mode to return a group of tags as a single message. In a scenario where I lose communication with the PLC, the module does not function correctly when communication is restored. When communication is restored, the module begins functioning again but all values from the PLC are returned as null.

The debug output from the module looks like this:

  1. Communicating correctly Debug: {"BE505Hazmon.HDSR.o_SensorData":59.67499923706055,"BE505Hazmon.HDSR.o_Fault":false}

  2. Loss of communication Debug: Error communicating with the PLC: Error: TIMEOUT occurred while writing Reading Tag Group.

  3. Communication restored Debug: {"BE505Hazmon.HDSR.o_SensorData":null,"BE505Hazmon.HDSR.o_Fault":null}

The values will continue as null until Node-Red is restarted or the flow is redeployed.

Note: If I use the mode "All tags, one per message" this issue doesn't present itself.

gfcittolin commented 5 years ago

Thanks for the report. I'll try to simulate it here, and eventually I may ask for more details then.

jpillman commented 5 years ago

It's a great module and you have done some good work on it. If I can be of any assistance, just let me know.

gfcittolin commented 5 years ago

Finally I had some time to simulate the issue, and looks like it should be fixed now. Could you install the just released 1.0.1 and try it?

jpillman commented 5 years ago

That fixed it! Thank you!