OT: Looking for sub msec resolution timer

Hi All,

I am in need of a way to measure a pulse that will have an approximate duration of 7msec. I would like to have a resolution of 0.5 msec but could probably live with 1msec.

PLC will likely be Eaton/Moeller XC-201 which has some interrupt inputs but I am not familiar enough with them to know if they will work for me or not. I know I can call a routine on the interrupt but I don't know if I can get to a high resolution tick in the OS with a know duration to make an intelligent calculation.

Anyone come up against this?

Thanks,
Norm

I found this guy

http://www.electronumerics.com/micro/micro-timer.htm

Looks pretty good

Last update. The other company is not open on Fridays so I found this one:

http://www.laurels.com/stopwatch.htm

Supposedly still made in the USA.
Online all manuals.
and price configuration.

Even has Modbus/TCP as an option!

with a PLC this wont work as the cycle time is too long and not steady due to communication etc.
try an arduino it is running 1 MHz cycles.
the output can be or digital or a PWM analog signal.
Or you can use an old type IC 555 to change the signal from digital to analog.
or indeed a unit like you suggested and put the signal analog to your PLC.

I measure periods that a digital signal is high with an STB EHC (high speed counter module). User manual is here.

Period measuring is not the default, but it is an option. From page 62:


This is 'lego' IO - the parts snap together. It's not my favorite design of snap-together DIN rail IO but it tends to be relatively inexpensive and there are head modules with ModbusTCP, CANOpen, and EtherNet/IP (I think others, but this is all I use). One of them supports RSTP, which is great for Ethernet rings.

I doubt this is unique to Schneider. I wonder do most other high speed counter modules support this type of period measuring mode?