Modbus TCP Polling Delay

[Daniel]

Modbus is master slave protocal which means master asks for one value and slave is replaying. Once answer is received then it asks for next value and so on. All this is a single process with single queue for all TCP devices. If a device will not answer in time then you have to add timeout which master will wait for the answer. With TCP the timeout is 3seconds. There are ways to do a block read which can speed things up and then at once you can read multiple registers. Not every slave supports this. See example here
https://forum.logicmachine.net/showthrea...4#pid21834