HMIS5T as a slave and M221 as a master on serial Modbus RTU

[alpikon]

Hi all,

Looking for advice how to set up HMIS5T as a slave and TM221C16R as a master on serial Modbus RTU.

Required to stop cycle and reset all timers down to 0 on M221 in case lost of serial communication between them.

For now HMIS5T as a master and M221 as a slave runs with no issues,  after serial 485 cable unplugged the cycle executions continue. Was tried setup with Modbus slave RTU driver on HMI and M221 set as slave- no communication. 

[Bastian_Schmitz]

I would suggest that you check instead these system words.

I did not test the function, but I would expect you could check in this way if the HMI is not present. Because in that case the number of messages will not change. 

[alpikon · Accepted solution]

Well, will use your suggestion. Also my initial question still valid.

There screenshot of setup M221 when system frames not received from HMI.

[Bastian_Schmitz · Accepted solution]

Your solution seems for me valid.

[ismailozinan]

[alpikon]

The HMI goes into error if serial unplugged any way. But M221 as a slave continue executing code. To prevent this my solution send M221 to stop all things due to serial communication issue. Physically only one I0.0 has M221 as a emergency stop button, reset of inputs are on HMI side.