Help!! regarding protocol

Very new to protocol programming, can someone help me on this...

$~(R(DM 5100),24)

What do the above indicate? It's type is Variable ASCII Reverse(What is this!?).
And Correct me if i'm wrong, R(DM 5100) implies read data from DM 5100?
How about the 24 following it? What is Primary Expression?
what is yN+x

Is there any source regarding how to program protocol? Thanks folks!

Where have you taken this statement from? What programming or configuration language is it written in? If it's a communications protocol command, what are the two elements that are trying to communicate (PC<->PLC, PLC<->PLC, duck<->monkey etc )?

A little more information might set someone on the right path.

regards

Ken.

See here:
protocol Help! @ MrPLC.com

Now how was I supposed to know that, Jay-A?

Ketaciturn posts a question in an Omron forum, gets an answer at 9:20am from Sleepy Wombat, then reposts Sleepy's answer in a general PLC forum (this one) 16 minutes later without any hint where he'd got the first set of info or that it might be Omron-related. Ask around by all means, but this scatter-gun approach to seeking help wastes a lot of collective effort! There are a lot of dogs chasing one rabbit.
If I'd know it was Omron I'd have stayed well away - not my comfort zone at all.

Ken

Lighten up, Ken - It's the newbies, not the experts, who have us chasing our tails. BTW, it's two o'clock in the morning in Sleepy's territory. Wonder what he's doing up?

Sorry, Jay-A.
Bad-tempered grumpy middle-aged Scotsmen - dontcha just hate them??!

Ken

No problem, Ken.

Bad-tempered grumpy middle-aged Texans - dontcha just hate them??!