limits when LM as Modbus TCP slave

[ikhy]

Thanks a lot for the LM resident script like Modbus TCP slave! We can use 125 registers at a time, right? what can i do if i need to read / write more registers? what are the limitations in this?

[admin]

125 registers is ModBus standard limit. But it only applies to a single request. If you want to read/write more then send several requests.

[ikhy]

125 registers is ModBus standard limit. But it only applies to a single request. If you want to read/write more then send several requests.

thanks! but what about addressing with multiple requests? will the address of the first register in the second request be 0 again? oh, understand addressing continues

[admin]

Each read request has a starting address and a number of coils/registers to read. The starting address is an absolute value and it does not matter which address was used in previous request.

[ikhy]

so no limits? 65536 registers can be polled?

[admin]

Yes, the whole range can be used.

[ikhy]

thank you!