Configuring Physical I/O
As delivered, the NFCS has a few channels of physical I/O configyred. The first four sensor inputs are set up as 'P1 Channel 1' through 'P1 Channel 4'. The last two discrete inputs are connected to the user-definable front panel switch as 'User Switch Up' and 'User Switch Down'. Finally, the last four discrete outputs are connected to the four user definable LEDs as 'LED 1' through 'LED 4'.
The preconfigured inputs and outputs are fine as they are, and can be left alone other than perhaps giving more descriptive names to the sensor channels. However, the necessary discrete inputs and outputs have not been defined. The first step is to define the physical inputs and outputs that will be used, and to give them meaningful names.
In order to do this, click on the 'Physical I/O' tab, which gives a view of the actual I/O that is available on the system.
This page shows each input and output and identifies the physical panel and connector where that signal is available. The name is a concatenation of the I/O type, number, panel number, connector number, and channel within that connector (for connectors that carry more than one channel). Other information is also shown including current value.
As described in the Programming Guide, NFCS rules are based on data elements which include physical I/O. The first step is to create data elements for the physical I/O channels that are going to be used. The 'Create Element' link is displayed for any physical I/O which has not yet been assigned. Simply click that link for the first three analog inputs, the first discrete input, and the first four discrete outputs. This creates the associated data elements.
Notice that the data element names have been set to the hardware channel name. This is convenient for keeping track of which cable the signal is on, but it's not ideal for readability. The next thing to do is assign human-readable names to these data elements.
Click on the 'Data Elements' tab to allow editing of element names:
Type in more useful names for each channel. Simply press 'Enter' or click the update button after each entry - edits must be done them one line at a time.
Of course, it's important to make sure that the name matches the actual physical location or connection.
When complete there should be a list of data elements that looks like this.