Modbus RTU Server is a completely free advanced emulator of devices supporting Modbus RTU protocol in slave mode. Using this product, user can reproduce on a single machine a real data acquisition system connected to the single media. Moreover, Modbus RTU Server supports simultaneous emulation of several devices at the same time.
Holding and Input Registers
Currently, the server supports 0×03 and 0×04 functions of Modbus RTU protocol for reading register values and 0×06 and 0×10 functions – for writing.
Working with Values
To be as close as possible to the real environment, the server works with whole values but not with separate registers. User is able to configure own set of values for each device to emulate different device types.
Each value has a “type” property defining the size of value data and the way this data is translated. Currently, there is a support for the following value types:
* 16-bit integer, signed and unsigned (1 holding register),
* 32-bit integer, signed and unsigned (2 holding registers, most significant word goes first),
* 32-bit single Precision float (2 holding registers, Reverse order of data words).
Single device can contain crossing values. This means that data of different values can be stored in same registers. Users can use it, for example, to see the representation of floating point value in integer form.
