high speed inputs

[mizinia]

Are the high speed inputs really different that the other inputs? or do they just have the logic pre-built for count and rate?

If they are different... I understand the HSC can handle up to 5000 pulses per second. What rate can the other inputs handle?

 

Thanks in advance.

[Joe Tauser]

The high speed inputs are connected through circuitry that will allow buffering of high speed signals.  The upper limit on speed is determined by which module you use - the new EXF-RC15 can go as fast as 200 kHz if you have a push-pull output to drive it.  They can be used as regular inputs if you don't configure them for high speed in the Hardware Configuration.

 

The other inputs are limited by scan time and they have to be on for a full scan as well as off for a full scan to work.  My experience has been you can use them up to about 400 Hz.

 

Joe T.

[mizinia]

Thanks Joe.

 

That is great news I think I will be in the range of 50-100 Hz but need 12-24 inputs at that rate. Would using the Unistream have any advantages over the V1040 when controlling the expansion modules? I see the EXF-RC15 is only for the Unistream CAN interface. But for others such as IO-DI8-RO8-L (would prefer to not have to convert to 24v if not necessary) is performance limited by the controller or the expansion module?

 

[Joe Tauser]

The EXF-RC15 is a stand-alone CANbus module.  It works with either Unistream or the Vision series.

 

You get your fastest response using a V1040 with a Snap-in Module where they are treated as local I/O.  To get your 24 inputs use a V200-18-E62B, which has 30 digital inputs and 28 transistor outputs.

 

Read the Help on the 1.25 ms Interrupt routine and the Immediate Input function block.  Put those two together and you magically get 400 Hz response time on all your local inputs.

 

Joe T. 

[mizinia]

thanks again Joe