Test digital outputs on a failsafe s71500

Kataeb

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how can we test digital outputs on a failsafe s71500 plc, using a watch table or other ? we need to make sure that each output is correctly wired .

SIMATIC S7-1500F, CPU 1516F-3 PN/DP, CENTRAL PROCESSING UNIT WITH WORKING MEMORY 1,5 MB FOR PROGRAM AND 5 MB FOR DATA, 1. INTERFACE: PROFINET IRT WITH 2 PORT SWITCH, 2. INTERFACE: PROFINET RT, 3. INTERFACE: PROFIBUS, 10 NS BIT-PERFORMANCE, SIMATIC MEMORY CARD NECESSARY 6ES7516-3FN01-0AB0

SIMATIC S7-1500, FAILSAFE DIGITAL OUTPUT MODULE F-DQ 8X24VDC 2A PPM PROFISAFE; 35 MM WIDTH; UP TO PL E (ISO 13849-1)/ SIL3 (IEC 61508) 6ES7526-2BF00-0AB0

SIMATIC S7-1500, DIGITAL OUTPUT MODULE DQ 32 X 24V DC/0.5A HF; 32 CHANNELS IN GROUPS OF 8, 4 A PER GROUP; SINGLE-CHANNEL DIAGNOSIS; SUBSTITUTE VALUE 6ES7522-1BL01-0AB0
 
I don't understand what you mean by your question.

Do you want to check if the relay is connected to the correct actuator?
Do you want to check if the output of the PLC is connected to the correct relay?
Do you want to check if a certain tag is connected to the correct output of the PLC?

For the first two, you need a multimeter to check the wiring.
For the last one, a cross reference table should be what you need.

Or do you have redundant outputs set up in the PLC and want to confirm the functionality?
 
For the regular outputs you can definitely force them on and off.
You find the force dialog under the "Watch and force tables".
Notice: Either be sure that the outputs cannot damage or hurt anything or anyone, or remove the power from the outputs (by switching off electrical, pneumatical and hydraulic power).

For the safety outputs, I dont know.
 
Sorry to ask, but is this a new system?

My experience with new systems is that the person wiring the panel would check that the wires from the PLC to the relay matched and sign off on a sheet that these checks were done (or highlight it in the drawing).

You could do a force of the output like Jesper said or find wherever the output is used and (if programmed in STL) put a SET instruction in the line above. Just make sure that you don't save this modification and that you revert back to the original of the machine.

Watch is to watch the variables in the PLC, force is to force them to a defined value.
 
Watch tables can monitor/change values in the PLC, but a change is generally (unless you get into some crazy settings) overwritten by any active code in the PLC or by the reality of IO. They can be useful as a mini-HMI you can change as needed. They are mostly intended for triggering internal tags (DBs, M bits) but can also be used for IO.

Force tables are intended for more permanent changes (maintence override, etc). They light up an LED on the PLC indicating that a FORCE is active, I guess in the hopes that someone fixes the machine and takes the force away eventually. A force overrides the PLC program/IO updates.
 
to be able to change the status of safety outputs (FDQ) , i had to go to "Safety Administration" > "Settings" > "Safety mode can be disabled" . when i went online , i could change the standard outputs value , but not the FDQ's (in the watch table) . so in the safety program block, i made a logic of memory bits controlling the FDQ's . et voilà ...
 
As you figured out, you can not force safety IO. If you try to do it, your CPU will stop.
 

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