Basic question to the PLC cycle - Modbus Communication

[Daniel_EWW]

Just to get a better system understanding...

I assume, the the PLC cycle is the following:

-> Read inputs

-> Execute the ladder logic

-> Write outputs

I am interested in the following:

- Modbus slave request. Is this done at the end of a cycle or asynchronous to the logic execution? (Data consistency)
- Modbus master periodic/ aperiodic. Is this done at the end of a cycle or asynchronous to the logic execution? (Data consistency)
- HMI display. Are the displayed values updated at the end of a cycle or asynchronous to the logic execution? (Data consistency)

Thanks,

Daniel

 

 

[Flex727]

Did you check the Help file? Starting up UniLogic can be a bit of a chore, but I happen to have VisiLogic running and find this in the Help file there: