Drive inputs of a plc using S7 1200

Import of a technical question from the user abid12:

abid12

Hello, I want to know, how can i drive the Inputs of another plc using the Outputs of s7 1200
here other plc is a non-siemens plc and i want to connect it hardwired. 

could you please tell me the Connection procedure.

Import-User-1

Import of a technical question from the user abid12:

 

abid12

Hello, I want to know, how can i drive the Inputs of another plc using the Outputs of s7 1200
here other plc is a non-siemens plc and i want to connect it hardwired. 

could you please tell me the Connection procedure.

 

With more information there will be more variations of answers.

When working with an unknown PLC that does not share a (24V) power supply..
Have the S7-1200 outputs connect to coils of relays which in turn switches the other PLC's own reference voltage (NPN: voltage low or signal ground, PNP: voltage high or 24V or Vcc).

Helpful?

Hi William. I have a safety plc which has 24v powersupply. i want to exercise it's inputs by harnessing it to siemens s7 1200 

I am not sure how to give the connections between plc's

abid12

Hi William. I have a safety plc which has 24v powersupply. i want to exercise it's inputs by harnessing it to siemens s7 1200 

I am not sure how to give the connections between plc's

 1. Do the safety PLC and S7-1200 share the same 24V power supply or do they have different power supply units?

2. Do you need to connect the inputs to both safety PLC and S7-1200?

3. Could you show a sketch (image) showing how the inputs are currently connected to the safety PLC?

Hi William,

Yes, the safety PLC ans s7 1200 have seperate powersupply units,

I don't have to connect any inputs to s7 1200, i would control it using some on/off buttons. i want to connect the outputs of s7 1200 to my safety plc such that it triggers the sensors connected to the safety plc inputs. 

the output result of safety plc, i can see through LED's.

sure, i will come up with some pictures tomorrow. 

thank you.

abid12

Hi William,

Yes, the safety PLC ans s7 1200 have seperate powersupply units,

I don't have to connect any inputs to s7 1200, i would control it using some on/off buttons. i want to connect the outputs of s7 1200 to my safety plc such that it triggers the sensors connected to the safety plc inputs. 

the output result of safety plc, i can see through LED's.

sure, i will come up with some pictures tomorrow. 

thank you.

 At face value... what I am understanding from your explanation seems wrong.

A safety PLC is used as it is more robust than normal PLCs; it is used for critical (safety) control. Placing a normal PLC in the loop can break down the advantages you have for using a safety PLC.

You will have to answer yourself the design question: if the outputs of the S7-1200 is not working properly, how will it effect the safety of the system? THIS also includes faulty logic in the S7-1200 as well as faulty switch gear (relay).

You will have to explain your intent VERY clearly before proceeding.

Hi william,

I am just tryinf to verify the functionality of safety plc by harnessing it to a s7 1200. it is just a newly designed one. just for testing i am exercising its inputs using the outputs of s7 1200. i have attached the pictures of the same.

the safety plc is connected with three sensors. E_STOP button, Safety doorlock switch, and a magnetic switch.

for now, i have nothing connected at outputs of s7 1200. i hope you understand it now.