Modbus Communication


Thread Starter


We want to check the communication between our device and personal computer, so we need the 232 communication software.
If your PC does not have an RS-232 port (many recent model laptops do not), buy a USB-RS232 converter. It requires a driver for your Windows OS. Get one from an outfit that handles industrial controls, not a cheapie from ebay.

For testing software, buy a Modbus master like "Simply Modbus" or Win-tech's "Modscan 32" or "ModPoll", all can be purchased and downloaded from the 'net.

Configure the comm parameters on both the device and in the software, then try to read a register.


Daniel Chartier


2 suggestions, Google for:
- Modscan
- Modtest

Both are free.

Hope this helps,
Daniel Chartier

Steven Smethurst


There are a few free utilities to check communications between your PC and your Modbus device.
If your PC does not have a RS232 port (AKA serial port) you may have perchance a USB to rs232 converter, Any Staples or Best Buy will have one.

Free utility to test your BACnet devices

Once you download and install the utility you will have to configure both the device and your utility to have the same communications settings.
Then it’s as simple as trying to read one of your registers on your device.

- Steven Smethurst