Modbus Tester

Using this program you can test communication with modbus slaves. You can read 4XXXX/3XXXX registers, 1XXXX inputs, 0XXXX outputs. You can write 4XXXX registers and 0XXXX outputs. The data can be in many formats (hex, bin, int). The raw frame format is also avaiable at the spy page.

Fonte e mais detalhes aqui.