Hi all.
We have a programme reading about 20 inputs. We want 5 of these to be scanned at 50ms, the rest at 1 sec.
Even though the logic seems a bit reversed (i.e. a higher scan rate inside the slower scan rate of the main scan) - we are convinced our program adheres to the manual, and should work.
We have the main scan running at 1 second, and nested within a subscan running at 50ms. No matter what we do we can not output the subscan readings to the datatable faster than 1 second. It doesn't sound logical to me, but the manual states that SubScan is to be used when certain analogue readings are required to be taken at a faster rate than the main scan, or am I missing something?
We've dodged the issue (in a very unsatisfactory way) by reading all channels at 50ms, and then only outputting the 5 channels we wanted reading at 50 ms on their own, into their own table.
My colleague assures me on the CR23X he could use dual scan rates and have a single table produced. We are using a CR3000 for this job, obviously through CRBasic.
Thanks for your help.
Mike.
Make sure that you call the table from within the Subscan construct. Also, make sure that the DataTable's DataInterval statement has zeros for the first three parameters:
DataInterval (0,0,0,10)
This will setup up the table to output every time it is called.
With that all said, it might be better to use a SlowSequence scan for your Slower measurements.
Hi TD,
Thanks for reply.
Sorry, I should have mentioned that we can't use SlowSequence as we need to read some pulse counts.
I shall try your suggestion tomorrow at work......I've tried many things, but can't remember whether I tried this or not.
Regards,
Mike.