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Guest bryon

s7 plc keeps locking up

11 posts in this topic

i have a s7 plc using breckhoff i/o's and a lotus touch screen. about once a day the touch screen will not respond. the picture still changes and moves but the machine will not go in to production, lift the doors, etc..... the only way to fix this situation is to turn the power off to the machine and restart it. some times this is all it needs other times we have to reload the memory card to get the machine to run again. this is a big problem because when we do this we loose all our setting for that job and have to start over again. i would give more info on the actual program but it is in germany and does us ( and the people who built it ) little good. has anyone else seen anything close to this before? how did you solve it?

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Hi, you provided us with very limited information about your problem. What hapens with CPU after the machine has been locked ? Is it still running or is stopped ? Does any errors exist on the CPU ? Can you check what is in CPU diagnostic buffer ? Is the touchscreen still communicating with CPU after failure ? Answer this question so we could quide youi in right direction.

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and what model of PLC? the new 317-2 PN/DP is sposed to have a similar problem to this. (stated in an official release from the Siemens website)

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.... what is the breckhoff i/o's ??? and for what cpu?

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I assume that'a typo - it's probably Beckhoff, it's a Siemens clone which is fairly common here in Germany.

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RMA, why are you calling Beckhoff IO a Siemens clone ?

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We've got an older Beckhoff here at site where I'm working at the moment. The hardware is completely different from Siemens, but the S/W is essentially Step5. It's not quite identical, in particular timers and counters work differently, and there is to edge detection (which is a real pain in the neck). I don't know the pricing, but I assume it's cheaper than Siemens, (just about anything is cheaper than Siemens!) so for small to medium jobs it could be an interesting alternative, especially given that in Germany virtually everybody (apart from me - I spent 30 years on DCS) has worked with either S5 or S7, so there's no problem with having to get into new S/W. Cheers Roy

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Roy, IO is IO and you don't need programming S/W for it. And my filling is that bryon is using S7 with Beckhoff IO connected by some network (Profibus DP ?). Is that right bryon ? It's hard to call "interesting" alternative something what is programmed with S/W similar to Step 5. I'd call it "painful".

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Fair point, but they do have a CPU as well and I did explicitly say small to medium (read simple) projects, so I think under appropriate circumstances it could be interesting, if only from a cost point of view. The system I had to get involved with here is about 10 - 12 years old, so I assume they may offer an S7 clone nowadays. It does raise the interesting question of why he's using Beckhoff I/O with a Siemens CPU in the first place, is it via Profibus or do Beckhoff now supply plug in compatible H/W as well? By the way that should have read "no edge detection" not "to", I would have corrected it but they've disabled the "Edit" facility here for some reason. (I know from another forum that the Invision S/W has the facility). Cheers Roy

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just went down to have a look at the Beckhoff system, since it's about a year since I worked with it. My memory was playing tricks, they don't have their own CPU, it's a PC emulation. My comments on its usefulness in appropriate circumstances still stand though. Cheers Roy

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I've had a look at the Beckhoff website in the meantime and they now offer an IEC61131-3 compatible system, I guess you could say it's an S7 clone now then. The old system was called SCOM5, so it was pretty obvious what it was aiming at. Cheers Roy

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