Step 7 help needed

GEOFRA · Oct 13, 2005

Hi everybody!
I have a problem with program monitoring in STEP 7.
I have an OB1 from which I call five FCs. There are only 5 networks in OB1 used to unconditionaly call the FCs and nothing more.
If I open any of the FC and click on monitor button (the one with the spectacles sign) I can see the program running and the values changing affecting the necessary outputs and everything is perfect.
Unfortunately I cannot do the same with OB1. If I open OB1 the monitor button becomes faded grey (disabled) and I cannot monitor it. There is not any sign of fault or any message from the CPU.
Any ideas?

XbIK · Oct 13, 2005

It seems like you made some changes and didn't load OB1 in PLC or your PC is not powerful enough to monitor several functions simultaneously

marius · Oct 13, 2005

XbIK said:
It seems like you made some changes and didn't load OB1 in PLC or your PC is not powerful enough to monitor several functions simultaneously

Normally step7 when user tries to monitor network and different block version is detected in PC and CPU asks for an overwriting of it ... so i don't think it should be this problem

... anyway sometimes i have to wait few seconds if i'm using serial-mpi adapter, simply because it's slow, CP5611 is much better solution (what's your PG/PC?)

... gray color always mean that program is not going through the visible branch (if using LAD) (in STL there are zeroes on right side) ... you can try to monitor in LAD as well as in STL !

... try to click on the network in OB1 and press F5 (refresh view) if it do something ...

... it can be caused simply by something else, like programmimg error ... but you maybe need to put here more info

jvdcande · Oct 13, 2005

Geofra,

you cannot monitor more than one block at the time. But if you close the block while monitoring, the communication point isn't released. So make sure you always leave monitoring mode BEFORE closing a block. I see this situation occurring often with my trainees.

Kind regards,

PLucas · Oct 13, 2005

jvdcande said:
But if you close the block while monitoring, the communication point isn't released. So make sure you always leave monitoring mode BEFORE closing a block.

That is something that I have never noticed before, that's a good bit of information to store in the ol' grey matter.

Thanks Jean Pierre

Paul

RMA · Oct 13, 2005

Interesting point JP, I'm running S7 V5.3 SP2/3 and I'm pretty sure that I've occasionally shut down an FB/FC while viewing it and never had any problems. I wonder if this is version dependant?

SimonGoldsworthy · Oct 13, 2005

jvdcande said:
you cannot monitor more than one block at the time.

I have always been able to monitor more than one block at a time when using a 318 (and as many as I like when using the plc simulator !) - can you explain your comment further ?

RMA · Oct 13, 2005

The 318 is effectively a 400 CPU in disguise, so it's probably different from the other 300 CPUs in this respect. However, with my 317-2 DP, whenever I change from one window to another and want to monitor the block, I get a window which informs me that I must first shut down the current monitoring of F/O/xx, "do I want to do this" (assuming I've been monitoring another Block, of course). Having said that, I'm pretty sure I've never had a problem closing a window where I was monitoring a Block.

S7Guy · Oct 14, 2005

With the 400 series, I've been able to monitor up to five blocks at once. I will try it with a 315 tomorrow, and see what I come up with. In any event, if connection resources run out, you should get the message that RMA describes. I've never had to worry about disconnecting before closing blocks.

jvdcande · Oct 14, 2005

RMA said:
Interesting point JP, I'm running S7 V5.3 SP2/3 and I'm pretty sure that I've occasionally shut down an FB/FC while viewing it and never had any problems. I wonder if this is version dependant?

Now that you mention it, it has been a while since I had to intervene in such a situation. It could be version dependant, but I didn't notice till now. It's surely something I have to look into in the next few weeks.

S7Guy said:
With the 400 series, I've been able to monitor up to five blocks at once. I will try it with a 315 tomorrow, and see what I come up with. In any event, if connection resources run out, you should get the message that RMA describes. I've never had to worry about disconnecting before closing blocks.

Well, it could be dependant on the number of connections that can be made. So far I have worked wit 313C-2DP and 314. These seem to have only one monitoring connection possible. I have no experience with S7-400 whatsoever. I did assume (without reason as it seems) GEOFRA was talking about S7-300.

Sorry if I assumed wrong, but this seems to become a very interesting thread.

Kind regards,

GEOFRA · Oct 14, 2005

Thank you all for your posts but I have closed monitoring of other FC so this is not the case.

What troubles me is that at the start of doing this project I could also monitor OB1 without any problem. At the start even though I had all the hardware configured in my project , I didn't have all the hardware installed. Now I have installed all the hardware including an interface IM365 module with some I/O cards on it. It seems to me that the problem started after installing all the hardware evn though I have double checked everything to have the correct part number and be at the correct position.

JesperMP · Oct 14, 2005

If you go online via the "accessible nodes", can you then open up and view OB1 online ?

hurricane · Oct 14, 2005

Very good point!!

GEOFRA · Oct 18, 2005

Finaly I have found that if I only have direct calls of FCs without any conditions then OB1 cannot be monitored and there is no need actually. If some conditions have to be fulfilled in order for the FC's to be called then OB1 can be monitored.

JesperMP · Oct 18, 2005

That makes no sense at all !
I have calls of subroutines without preceding conditions in my OB1, and I can certainly look into it online.

If the spectacles were greyed out at some time, then the reason was probably that the offline and online blocks had out of sync.

Step 7 help needed

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