Get analog input scaling with PAC Control or With Visual Basic

PAC Project
1

Hello, I need to know if there is any way to get the scaling of an analog input with PAC Control, or with Visual Basic communication SDK.

We need to put in graphics dynamically.

Thank you.

2

The memory map is your answer.
It holds pretty much every data point in the system.
You can access the memory map via pac control commands “Read Number from I/O Unit Memory Map”.
The same type of command is available in the Visual Basic SDK.

Here is an image showing the steps to get the data from PAC Manager.

  1. Put in the IP address of the rack that has the analog value you want the scaling of.
  2. Select Point Config from the menu.
  3. Select the module.
  4. Select the point on the module.
  5. Get the mem map address for the Upper Scaled Units.
  6. Get the mem map address for the Lower Scaled Units.
3

Perfect, just one question, the upper scaled units is correct, but the lower scaled units does not match, it is not real with its scale, as calculated?

Thank you very much for your attention

4

Sorry, just a little lost with this question… Are you talking about the screen shot, or your application?

If you mean your application, have you checked the upper and lower scaled units in PAC Manager?
Have you set both? You need to explicitly set them and then save to flash (either through PAC Control or PAC Manager).

5

Also note, when you use PAC Control to configure your points, this dialog box does some math for you then writes the appropriate corresponding values to the mem map as Ben shows above.

Here’s an example of some very simple scaling on a voltage input that represents Gallons, and has an Actual input range that’s only half of the Full Range of the module.

PAC Control configuration:

ScalledGallons.jpg401×502 48.7 KB

What got written by PAC Control into the mem map:

GallonsPACMan.jpg700×498 53.2 KB

Are you using PAC Control to do the calculation(s), I hope?
Can you tell us what you’re seeing in those views vs. what you expected?

6

Hello, I mean, I need to get the Memory Map “Lower Scaled Units”, but the value does not correspond to the scaled value of 4mA in PAC Control.
It can be obtained directly from the Memory Map?
Anyway I have solved using formulas
I attached explanatory Image and thank you very much for your service to the customer.

Lower_Scaled_Units.jpg700×326 43.4 KB

7

When you say “solved using formulas” I think you mean you read the “Upper Scaled Units” and “Lower Scaled Units” from the memory map, and worked backwards (the reverse formula PAC Control used to calculate those values from your given “Actual” and “Scaled” values).

I believe you were essentially trying to work-around the fact that the “SCALED” values you entered when you were configuring your points are NOT written to the mem map, nor are they anywhere else you can access in your strategy (besides that one “More Info” dialog you showed, which doesn’t help in the program).

Did I understand correctly? Perhaps having access to those values would be a nifty future feature I could suggest?