In a textile factory, we are using a Meyer RPS-E fusing machine which claims that "Emergency stop" is initiated. When I measure the emergency input signal ( at the 633P digital input connectorl ) I find that the emergency condition is not active. I have a feeling that the 633P mistakenly senses the input as active. If only I could see the "perceived" status of the input from the OP panel I would perhaps get on the right track...
I am not a "control" man... I am a straight programmer ( C/Basic/Pascal/Cobol/Algol.. etc. ). Therefore please forgive me if I have asked a stupid question... Thanks

 

Hello Semih BATTAL;

The C7-633/P is a composite of a Siuemens S7-314 CPU and a OP7 operator interface. So you can use functionnalities of both to visualise the state of your inputs.
You can use Step7, the programming software for S7 CPUs and connect to the programming port on the C7; create a VAT table and request the values of the addresses you need; or you can open the functionn (FC or FB) where the logic for those addresses is implemented, and monitor directly the state of those registers.
You can also use ProTool, the programming software for the operator interface, to set up a page that would display the values of the addresses you want to monitor. Download it to the OP port on the C7.

Hope this helps,
Daniel Chartier

 

Hi

It depends on if the screen setup includes the standard screen normally called status. If this is present you can look at the input stauses in byte or word form.

Andrew

 

I am not familiar with your particular machine. You have also not stated whether the machine is operating correctly, but giving an incorrect alarm indication, or whether it is in fact not operating.

However, in many cases an "emergency stop" signal operates opposite to other typical signals. That is, when a voltage is present, it is NOT emergency stopped, and when no voltage is present, it IS emergency stopped. That is, the signal may actually mean "NOT emergency stop".

The reason for this is so that damage to the emergency stop circuit (e.g. a wire comes loose or is cut) will cause a safe condition (emergency stop) rather than disabling the emergency stop. The the C7 controller will not itself be part of the safety circuit, but it is typical for the alarm input to be fed the same signal level as is in the actual safety circuit.

If the above is not of any use to you, please provide us with more information on what we can do to help.

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Michael Griffin
London, Ont. Canada
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The C7 panel from Siemens is actually a combination PLC and Operator Panel.

the easiest way to test if you are getting a momentary event is to program a Set-Reset "latch" in the Ladder Logic program. You need to buy the STEP7 software to access the program in the C7 PLC.

gary

 

Perhaps (which is normally the case in E stop circuit) the input is "not active" when E/stop circuit has been tripped (therefore brings up E/Stop tripped alarm). The input is required to be "active" when the E/Stop circuit is not tripped.

 

Hello Daniel Chartier,

Thank you very much for your kind reply.

Unfortunately we have neither Step 7 nor Protool software. As I said before, we are a textile company and we only have a single Siemens Simatic C7 series PLC, in short we are an end user. Because of this, I don't think we "should" have these diagnostic software/equipment anyway.
What I do not understand is: why does this sophisticated controller not have "some" diagnostics built in? Even Siemens LOGO and Mitsubishi Alpha series simple controllers have such diagnostic displays...

About our problem: It was only a blown optocoupler preventing the CPU from reading the inputs (on the "enable" circuitry of the input shift register). We were lucky, we simply piggybacked an ordinary optcoupler onto the faulty one and the PLC is working fine now...

Thank you again for your reply.
Regards,

Semih BATTAL
Computer Dept. Manager
Edirne Giyim Sanayi A. S.
Edirne/TURKEY

 

Thank you all who tried to help. I was not expecting this many answers.

As I described in my previous post: It was a faulty optocoupler in the C7-633P.

Thanks again.

Semih BATTAL
Computer Dept. Manager
Edirne Giyim Sanayi A. S.
Edirne/TURKEY

 

Thank you all who tried to help. I was not expecting this many answers.

As I described in my previous post: It was a faulty optocoupler in the C7-633P.

Thanks again.

Semih BATTAL
Computer Dept. Manager
Edirne Giyim Sanayi A. S.
Edirne/TURKEY

Dear Mr Semih
please help me with the same broplem
one of the Digital inputs of C7 633p is not changing status
so please how can I Know the optoucopler inside the HMI