PLC Modbus RTU slow response


We have a PLC connect by Modbus /RTU to a few Wiren Board WR modules /devices and when we have more than 5 units we start to see lack of speed on the response due to traffic increase in the Bus.

We are going to change the PLC software to Write to the BUS, only when it is really necessary, instead of being permanently send and receiving data. We will polling permanently only the inputs to reduce data traffic.

Is there any tip from your side to improve the response of the devices ? Would be nice to have a kind of " Smart Polling " in your Modules. So the communication would start only after a input change. Is there ?

How do you solve the issue of lack of speed when using your controller ?



Good afternoon.
One request and response (one register) at 9600 has a time of ~ 26 ms.
There are two ways - increase the speed to 115200 (register 110) or decrease the amount of data.

Good morning,

After performing
a few tests we have conclude that there is a huge delay in the input register when compared with counter register for the same input.** Is this suppose to be like this ?
Is this possible to fix ?

This issue was the main reason for the slow Modbus responde.