I have been working on a CNC controller for quite some time. I am most interested in the speed of the entire process and what it takes to increase the speed of that process. When I say speed, I am looking to decrease the scan time of a SNAP-PAC-R1. I say scan time because that is what I am use to evaluating in other brand controllers I have used in the past.
Let me explain what my current project entails.
I have 1 SNAP-PAC-R1 and 1 Touch Screen running PAC Display Runtime ( an All-In-One PC). This process involves 6 Axes (PID Loops) and about 32 inputs and 32 outputs.
The item that I have been monitoring lately is the “Loop Time” (if there is a way to monitor “scan time” I would love to hear any feedback on that). When I started investigating, my loop time was up to 300+ msec. I have condensed some things and now the process only runs 2 charts (it will never, ever be less than 2 charts) at any given time. I also reduced the amount of tags on the “Auto” screen from 210 floating point values ( with a refresh rate of 500 msec) to 130 floating point values (and a refresh rate of 2 seconds). With that said, I was able to achieve 30-100 msec loop time. This reading was taken with PAC Control in debug mode (Control Engine>Inspect). With 100 msec being the max, it usually sits between 30-50 msec.
After I achieved this, I could see increased performance of the entire system. Winning… (heh)
I then turned debug mode off in PAC Control and went to PAC Terminal (View>Status). I would monitor the Loop Time and it was at 16-45 msec (most of the time it was below 20 msec… Great.)
With all of this said, I am wondering the proper way to actually see how fast the R1 is executing the strategy. I know some controllers I have used in the past (and still use), the max scan time is 3 msec and actually run less than or equal to 1 msec. This is the value I want to see in the R1. Is this possible from some status value? Any input would be appreciated.