PLC-5 hardware (1771-DS)

Hello folks,



I am wondering if some of you here can help me understand how the 1771-DS Input latching card works. I haven't been able to find any documentation which explains this.



My main question is the relationship between the Pulse input and the gate input. Can somewhat explain how these interact?



Thanks

Must be a 'Black Hole' type of module, I can find absolutely no documentation on it.

That being said, if I remember correctly, the module itself was used to look at very high-speed inputs, and 'latch' the input image to guarantee that the PLC would see that there was a transition. In other words, it would hold the input active in the PLC input table for at least one complete scan of the processor, even if the physical input was of extremely short duration.

Sorry I can't help any more.

I found a 12-page "Product Data" booklet - publication 1771-2.68 dated May 1986 ... it looks like it has enough information to be at least mildly helpful ... keep a close eye on all of those jumper settings ...

Thanks folks. Ron, that's exactly what I was looking for. How the heck did you find it?

NEVER throw the old stuff away ...

How the heck did you find it?

Click to expand...

Allen-Bradley used to produce CDs called the "DataDisc Sampler" ... they were available for free and AB distributors would hand them out like popcorn at trade shows, etc. ... they were set up just like the documentation on the website used be arranged ... my set with copyright 2001 has many "oldie-but-goodie" publications that are no longer available on the "new-and-improved" AB website ... luckily the information you needed was on the old CDs that I'll NEVER throw away ...

glad we were able to help ...