How to read/write two bits status in modbus?


Thread Starter


We have two processor based systems are there. One system is connected with field. And another system will communicate with it. The field data consist of points of railways track. And each point has normal, reverse, free, and moving.
We want to map it as 00-normal, 01-reverse, 10-free and 11-moving. We want to read/ write these two bits status per each point through modbus. For example if we take it as coil then each coil has one bit but these points has two bits. Shall we take as 2 bits coil or discret input or not?
In standard modbus each Then from which function codes we can do this.

Please suggest us.