PLC | RS485 to use HMI communication is the best choice

In the last article written, because the relationship between the PLC scan time,
Makes the communication time <scan time,
A lot of time wasted on the PLC scan time.

The HMI is to use the firmware to handle the communication, to avoid the problem out of the PLC scan time.

If you use the HMI to do RS485, another relative problem will occur.
1 HMI communication with the PLC's different way of writing.
2.PLC, HMI & control of both sides of the program, follow-up would be more trouble Debug.
3 HMI will usually far away from the other components, interference issues to consider.