poeterdebier
Member
Hello guys,
I got a question. I have a Wago 750-841 with some modules. I try to control the PLC using Modbus TCP which is working great so far. I use the Modbus plugin for Node-red and managed to write and read digital and analog inputs/outputs.
Now, some people suggested that using a program on the PLC is more robust and less prone to failure like for example a Raspberry Pi (using the Rpi as a master, PLC as a slave).
So I decided to upload a simple test program using Codesys v2.3. This is also working (outputs reacting to inputs etc). Now the problems are starting: I noticed that after the program is loaded the PLC is not reacting to command from Node-red anymore, which previously where working! Even after resetting the PLC the command are not working. Only after I change the module layout and make a new ea-config.xml file the Modbus commands are working again (no program on the PLC).
Is there somebody who could give me a hand with this? I would like to be able to send simple command using Node-red but also be able to put some programing inside so that I can control devices/appliances directly from the PLC (not dependent on Rpi or some other control device).
many thanks,
gr Piet
I got a question. I have a Wago 750-841 with some modules. I try to control the PLC using Modbus TCP which is working great so far. I use the Modbus plugin for Node-red and managed to write and read digital and analog inputs/outputs.
Now, some people suggested that using a program on the PLC is more robust and less prone to failure like for example a Raspberry Pi (using the Rpi as a master, PLC as a slave).
So I decided to upload a simple test program using Codesys v2.3. This is also working (outputs reacting to inputs etc). Now the problems are starting: I noticed that after the program is loaded the PLC is not reacting to command from Node-red anymore, which previously where working! Even after resetting the PLC the command are not working. Only after I change the module layout and make a new ea-config.xml file the Modbus commands are working again (no program on the PLC).
Is there somebody who could give me a hand with this? I would like to be able to send simple command using Node-red but also be able to put some programing inside so that I can control devices/appliances directly from the PLC (not dependent on Rpi or some other control device).
many thanks,
gr Piet
