Needed 4 high speed counters in BRX

[Garyhlucas]

We switched from Do-More Terminator with a CTRIO card to BRX and were caught off guard by BRX only having 3 high speed counters built in.  We have 4 flow meters that pulse too fast for general inputs, what to do?

I set one of the high speed inputs to trigger an Interrupt.  In the interrupt routine I count to ten, pulse a C bit and reset the counter to zero.  that C bit drives a FreqTmr block at a rate that works in our 5ms scan time and we have the flow rate we need.  Seems to work pretty good so far.

Anyone see a problem with this?

[Mike Nash]

Good save.

I had to look and see because I was thinking of a job we had 3 H2-CTRIO2 modules for 3 axes (1 per axis, though 2 modules would have worked.) A single BRX could have done all three with Step/direction and quad encoder feedback too. I was thinking 8 high speed inputs, but I see the 3 counter restriction.

It must be a very busy program to run 5mS on a Do-more. I put the PLC scan time on the C-more on the 3 axis job and it runs around 2.5mS. I usually forget to look at the scan time on while on start-ups.

[BobO]

New BRX HSIO module coming in the next few months.

[Garyhlucas]

I just noted the scan time when I was trying to solve this problem so no effort has been made to see if it could be better.  We have about 10 analog inputs, 4 high speed inputs, 4 pulse outputs, that are not real fast, and 5 VFDs on PID loops communicating via Modbus, and a C-More that does continuous logging of data.  My suspicion would be that the way I implemented Modbus is huge resource hog.  I do use stages everywhere possible.

One thing to consider is that our product is a tiny membrane waste treatment plant rated at 10,000 gpd but the reality is it has virtually identical I/O to a 5 million gallon a day plant, so maybe not too bad.

[DLTimmons]

Any time line for the HSIO?

[BobO]

Soon. I'll send you a PM.