Multiplex DH+ Global Status Bits

[Steve Wiebe]

Hello All,

I have a dozen PLC-5s connected via DH+.
I use Global Status to share various bits of data between the PLCs.
I would like to expand this without resorting to messages (to keep DH+ traffic down and speeds high) and was thinking of multiplexing data.
I know I could program this but hey, why re-invent the wheel.
I was wondering if someone had some examples they could share with me?
TIA,
Steve.

 

[Mickey]

Hello All,

I have a dozen PLC-5s connected via DH+.
I use Global Status to share various bits of data between the PLCs.
I would like to expand this without resorting to messages (to keep DH+ traffic down and speeds high) and was thinking of multiplexing data.
I know I could program this but hey, why re-invent the wheel.
I was wondering if someone had some examples they could share with me?
TIA,
Steve.

I have seen a value written to the global staus word, to represent different conditions. I'm not sure that would be any less programming but it was simple to understand. If you think about it you could have 65000+ different conditions. ( I know, that would be getting a little carried away)

 

[Oakley]

If you do this, be sure to document this within your program (or even an external document that throughly explains it).

I once did a plant wide load shed scheme using multiplexing. Throughly documented it, then when the yahoo that came after me couldn't figure it out, just went over the documentation with him.