Station S7 400 connect profibus with ET200

[plc_cnc]

I have station PLC S7 400 connect with ET200. And I have a question: if ET 200 occur error: loss supply. I'm not sure, all station PLC stop?

 

[balash]

i'd say yes, if no OB8x routine(s) is programmed for such a case to bypass it...

 

[JERA]

Use OB82, OB83, OB86 and OB122
Just download the blocks to the PLC - no program needed in the blocks

 

[JesperMP]

Use OB82, OB83, OB86 and OB122
Just download the blocks to the PLC - no program needed in the blocks

In my opinion, at the very least the error OBs should contain code to generate alarm messages.

 

[balash]

agree with jesper. at least it would be desirable to read the error and perhaps to log it (and show it on HMI).
if these OBs are needed (ie PLC shouldn't go to stop on profibus error), then the alarm when the error occurs (and is bypassed) is welcomed.

 

[JERA]

In my opinion, at the very least the error OBs should contain code to generate alarm messages.

Correct. All blocks can contain code for generate alarm, but it depend of the application / plant.

If the blocks don't have code the PLC will not stop at ET200 error, and no alarm is generated.

 

[Daye.04]

Correct. All blocks can contain code for generate alarm, but it depend of the application / plant.

If the blocks don't have code the PLC will not stop at ET200 error, and no alarm is generated.

Exactly - I'm fairly certain that's jesper's point. An error shouldn't just be bypassed. It should at least generate an alarm

 

[plc_cnc]

Thanhks all for anwser,

I agree OB87 (Communication fault). But, I don't know write program in OB87 for interrupt ET200 station error.

 

[dchartier]

Thanhks all for anwser,

I agree OB87 (Communication fault). But, I don't know write program in OB87 for interrupt ET200 station error.

Hello plc_cnc;
OB 87 will not help you for your problem. The ET 200 is considered a Profibus slave station, and will cause OB 86 to be called when it loses contact with the DP-master.
look at Jera's earlier post, suggesting to Use OB82, OB83, OB86 and OB122. Just add these to the programming blocks and download to the CPU, then open the diagnostic buffer of the PLC when the SF/BF LEDs become active to locate the source of the error.
Hope this helps,
Daniel Chartier

 

[plc_cnc]

Thanks DChartier,

I'm not sure. After ET200 occurs error, S7 400 station still run if I use OB82, OB83, OB122,

 

[dchartier]

Hello PLC-CNC;
Look at chapter 23 "Diagnostics" of the following manual:
Simatic : Programming with Step 7 v.5.5
You will find a description of all the diagnostic OBs, individually, with information such as this one:

If you do not program (note: this meand created and loaded to the CPU blocks) OB86, the CPU changes to STOP mode when a rack failure is detected.

If you look at it another way, the statement means that if OB86 is loaded in the CPU and a rack failure occurs, the SF and BF LEDs will light up, but the PLC will not go to STOP mode.

Hope this helps,
Daniel Chartier

 

[plc_cnc]

Thanks Daniel Chartier,