Modbus Poll 13.2.1.2558
Modbus Poll is a Modbus master simulator
Witte Software software
DlSoftware247 lists 2 Windows programs by Witte Software, mostly System Utilities software. The most popular are Modbus Poll, Modbus Slave.
Modbus Slave 10.0.0.2493
Modbus Slave is for simulating up to 100 slave devices in 100 windows!.