Setting up equipment

For the Beta version of Whzan the PLC installation and the Modbus Gateway, the PLC must be connected via Ethernet.  Testing has been limited to the Crouzet M3 range of PLCs,  however the Gateway is being updated and tested with other PLC types.

The Whzan Modbus Gateway is available as a free PC Dowload from the Whzan Shop. You must have a registered Whzan account in order to make use of the data. If you a look at the Getting Started process on the Whzan site; it will take you through registration and account setup.

You will need to have given the Crouzet PLC an IP address and note that it communicates via port 502.

With the PLC connected and the Millenium 3 program in FBD mode, the Ethernet points are shown at the bottom of the programming page.  Inputs and outputs from the PLC are 16-bit Modbus words, however individual bits can be set using the binary-to-decimal and decimal-to-binary convertors. The example below shows how to send data from the PLC.

The Ethernet outputs have to be set to Numeric Outputs.  Individual digital bits are grouped using the binary-to-decimal convertor, and in this example, these are converted to a number with 'BIN/DEC'.  The four digitals shown will go to the least significant bits, hence O1 ETH has the potential data range of 0 - 15.  O2 ETH will represent the count value incremented at one second intervals.

Whzan can be set to pick up these PLC outputs either as digital inputs mapped onto individual bits or numeric inputs from whole words.

The screen image of the Millenium programming tools shows this stage:

The Ethernet inputs are the direct reverse, i.e. they have to be set to Numeric Inputs.  Individual digital bits are separated using the decimal-to-binary convertor 'DEC/BIN'.