PACsystems I/O mapping ALG628 card

I am a new engineer just graduated and have been tasked with 'documenting a gate station's I/O and functions'. I work for a large utility and these are Gas facilities. Mind you I hadn't the foggiest idea what that even meant 3 months ago and they haven't provided any training but I dove into Machine Edition and I think for most cards I can do a variable dump and between that and the terminal info get most of what I need - which is the Analog and Digital inputs and outputs and variables.


Except for the ALG628 cards. The variable dump for this one station, for instance, shows 4 variables of type AI_ALG628 and me has only channel 1 and 2 enabled. The 4 variables InPressure_Raw and Metering.InletPressure and OutPressure_Raw and Regulation.Outlet Pressure - so I feel these are actually just two instances each of two channels.


My question is: How do I know which variable corresponds to which channel?

Take a look at the hardware configuration for the module. It requires eight 32-bit Floating point variables for the eight channels plus four more 16-bit words for the HART data.
If it turns out that it is configured for addressed variables, then the addresses will be %AI memory. Each %AI memory location is a 16-bit word. A 32-bit floating point value will utilize two consecutive %AI addresses.
If the starting address for the module is %AI0017, then channel 1 will occupy %AI0017 and %AI0018, channel 2 will occupy %AI0019 and %AI0020, etc.

Thanks

Yes I got that part - in this case the Channel Value Reference Address is %AI00901 so its 901 and 2 for channel 1 and 903 and 4 for channel 2. And I actually just found that in the variables window if I get the properties for these variables they are structured types that include an int for channel - so that solves my own question.


Don't quite have my head around HART yet. I get that its carrying both digital and analog info but what exactly is contained in those 4 words?

Sorry, but I can't help you with the HART data. I've never had the occasion to work on any projects that utilized the features provided by HART.