ModScan is the original and still the best Windows application for testing and troubleshooting modbus devices. Beginning in 1990 with the release of Windows 3.0, ModScan has been around long enough to become the de-facto standard for maintenance of modbus networks the world over. ModScan operates as a modbus master allowing its user to send and receive data to and from modbus slave devices connected via tcp or any serial comm port. Both the ascii and rtu transmission modes are supported, as well as modbus/TCP and tcp tunneling. The companion application ModSim, operates as a modbus slave simulator and both applications are compatible with either IPV4 or IPV6. Download the free demos below.