In our PAC Control strategy written years ago, we have some Float variables like this which are used to send values from 0 to 10 (representing 0 to 10 VDC) to a device.
Here is what the corresponding Analog point looks like:
In the strategy, we have control blocks like this:
which limits us to just integers (e.g. 2 or 3, when we really want 2.6). This was done years ago when we barely understood PAC control. In hindsight, I think it should be:
Am I indeed correct that this is what I need to change? Before I redo the program with these changes, should I be aware of any unintended consequences?
Hi Grant,
What you propose is better than what is there. Analog outputs are Float type so it is more natural to send them a float value.
It doesn’t look like the float variable Weight Feeder Command VDC is being used. Thanks not a problem, but it may have been that it was added so that you could set the variable from various logic in the strategy and have that variable moved to the actual analog output (probably in just one spot).
When the projects get large it is sometimes better to not have multiple locations where the IO Points are read/written to. Writing and reading to/from IO is considerably more time consuming than variables. So it often works real well to have a variable that represents and syn’d to an IO point that is updated with the real IO value in its own chart. Then the rest of the project reads and writes to variable, and not directly to the IO Point.
Thank you Dave. That was the insight I was looking for. Everything you explained is clear enough now and I will make some changes on a limited basis to ensure the program runs without any glitches.
