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Technical support / MASTER-SLAVE Communication
« on: October 02, 2006, 02:27:48 PM »
I have decided to use the READMODBUS & WRITEMODBUS commandS. The example works fine and the commands worked fine when I installed them on the master PLC. I am able to input on one PLC and output to the other PLC. I am still not able to read my ADC channels from the slave to the master though. I programmed in the slave DM[1]=ADC(1)and checked the on line monitor to make sure I had a changing value when I adjusted the analog input. That worked fine. Then I programmed into the master PLC: DM[1]=READMODBUS(3,1,1001). I also tried using 1000, 1002 none of which gave me my #value for the ADC(1) when I monitored the master PLC program and changed the analog input on the slave. I also tried to have the READMODBUS command = an alphanumeric variable directly with no luck. I am not a programmer but this seems straightforward enough. Can you help?
It works now. I used the README2 command and I am able to read all 8 ADC into the master plc starting address 1000 worked for DM[1-8] ? offset 1000-1
It works now. I used the README2 command and I am able to read all 8 ADC into the master plc starting address 1000 worked for DM[1-8] ? offset 1000-1