ModScan is a Windows application designed for use in development or
maintenance of multi-vendor industrial data systems utilizing the
popular PLC communications protocol as developed by Gould Modicon.
It operates as a MODBUS Master device, accessing data points in a
connected PLC compatible slave device.  It is designed primarily as
a testing device for verification of correct protocol operation in
new or existing systems.  MODBUS data points, (coils and registers),
may be read and/or written from the ModScan application using MODBUS
Commands 01-06.  This Windows application will allow effective testing
of MODBUS Slave devices in either ASCII or RTU modes of operation.