Quantum 534 PLC Status Word

[drx 2]

Hello, I am actually adding PLC /network diagnostic on citect SCADA pages. So far, not much a problem. But after looking at the whole thing from above, I figured out a stupid thing. On these pages, I display the RUN status bit (and others) of the plcs, to do so, I use the STAT function and then read the register 4x in which the status words were copied. But say, if the PLC is not running, the program ain't neither, the instruction is not executed, then the register is not updated, and I'll display that the plc is running all the same because the register will freeze as it was before the PLC stopped... Here is were I need help, I can't find how to access the STATUS register directly, I don't even have the slightest idea of where it could be, I first thought the few firsts 4x were dedicated to the system but seems like not... With some other Schneider PLC there are %SWxx, but really can't find it in these Quantum ones, and if I could directly read into them with the scada ? Been roaming here and there on the web but couldn't find any answer but to use the STAT function... Could I be the only one to realize this snake is eating its tail ? On the other hand, I'm not sure the PLC would answer the SCADA's data queries if not running... And wouldn't try for this PLC hasn't been stopped for years being important for the factory... Does anybody have a clue about that ? Thanks.

[Crossbow 295]

I don't recall that information being available in a Quantum.

[cHud 25]

Attached is a unity help file outtake. If i remember correctly these system bits have always been the same with previous processors so it should also be on yours in same position. But do you have the programming software for that processor? Help file shows all the system words and bits. Alternatively you could create a heartbeat between scada and plc. With counter in plc. If Counter in plc and scada differ for x time then you know the link is down Edited 24 Dec 2013 by cHud

[drx 2]

Hi, thanks for your concern... The software is ProWorx32. Quite used to PL7 Pro, the %System words were the firsts I looked for but unsuccessfully. I could find out which bit of which word means what but cannot find where this STAT function reads the values from... For instance in the dataWatch window I tried all the keys from the keyboard to see what could be available, and it would take nothing but the 0x, 1x, 3x, 4x and 60x registers and # for constants Having a life bit is something I thought about but I was trying to be sort of elegant, if the information is available why not use it ? Anyway, I don't like it, but I'll never be able to be sure my reporting program works for there is no way to give it a try, stopping these PLCs is just impossible... It's all about faith Whatever... Wish you the best for Christmas, have a nice time.

[Crossbow 295]

cHud, % addresses are not found in the older units and Proworx. That information for Unity does not apply to his system. Best bet is as cHud recommended adding some code. I've made a counter which runs every scan for this purpose before. If the number stops changing, then the PLC is stopped or you are not communicating with it anymore.