ComTest Pro

ComTest Pro is an efficient and reliable piece of software created to serve as a communication test instrument for MODBUS RTU devices, supporting both Ethernet and Serial connections.

The interface of the program is very easy to handle, featuring three main steps that you need to follow, while the tabs let you switch between the two available connections modes to the one you are using.

ComTest Pro’s menus enable you to save or clear the logs, as well as read or write registers, or view raw data gathered by the application.

Subsequent to opting between ‘Serial’ and ‘Ethernet’ connections, you can begin configuring the utility’s ‘Steps’. In the case of the latter, firstly you can select the ‘Protocol’, either ‘Modbus TCP’ or ‘Modbus over TCP’, entering the ‘IP Address’ and ‘Port’ number, then setting the ‘Delay’ and ‘Timeout’ period in milliseconds.

The ‘Serial’ connection lets you choose the ‘Port’, ‘Baud Rate’, ‘Data Bits’, 'Parity’, ‘Stop Bits’, ‘Delay' and ‘Timeout’, being able to also activate ‘Echoback’, ‘RTS Control’ and ‘Reverse CRC’.

The ‘Step 2’ enables you to input the ‘Device’ and ‘Register’ numbers, then select the preferred command, with several options to use, specifically ‘Read Holding Registers’, ‘Write Single Holding Register’, ‘Write Holding Register’.

Next, you can set the ‘Function’ code and activate ‘Loop Command’ or ‘Error Checking’, optionally displaying an ‘Error Dialog’. The ‘Step 3’ section of ComTest Pro allows you to press the ‘Start’ button in order to begin gathering the relevant information. When complete, you can either ‘Copy Data to Log’ or ‘Copy Data to Write Registers’.

All things considered, ComTest Pro proves to be a handy and easy to understand tool that can successfully help you in testing the communication of MODBUS RTU compliant devices.