Can somebody please tell me how I can disable all inputs and outputs of a S7 200 PLC? I have incorporated a service timer that checks the date and when this date is true I wish to disable the program until the criteria is met and a valid release number is entered on the TP070 screen, which will then return the user to the normal operating screens.

 

For S7 200 plcs from siemens you will using Step7 Microwin software for programming .There is a utility called Status chart from where u can force the input/output to either "on" or "off".

If u want to achieve the same thing through program then you latch and unlatch Outputs.

 

What, one of your customers not paying their consulting bill? ;-) Why not just check the date, and if conditions are met, jump over the rest of the logic?

 

Do you want to disable all inputs and outputs - or the program ? Disabling a program - properly written for that - should have the same effect. Just use a MCR-like contact (MCR - Master Control Relay).

Meir

 

Hi,
I am not totally familliar with the S7 200, but i am with the S7 300. For testing and simulation of the plc program, i generally address map all inputs and outputs through memory address. You can do this bit by bit, or on word ant a time.
I call this function (FC) in OB1.
So, to enable or disable I make the "EN" parameter of the block true.

If you are programming in one function, you can do this in STL. Just use a Jump Condition "JC".
If the code is true the the addresses are mapped, if not the transferr is skipped.

I shouldn't need to tell you any more the rest just needs some programming intelligence.

Regards,
Paul.

 

Why don't you try replacing all of the outputs with internal bits and then
use a conditional (based upon your criteria) move statement to move the
internal bits to the outputs bits.

DA

 

Does the HMI or DAS synchronize its date from the PLC? If not, then disabling the program using the Date as the argument will be no use. If I am the end user, I would just reset the date in the PLC.

ANA

 

Disabling the inputs are unnecessary and it is very easy to disable the outputs: Just move zero to QD0, QD4... at the end of OB1 if the mentioned service condition meets (or does not meet).

The problem is, how will you match your next service timer after the correct code is entered? It needs some more code I think, but still possible.