I am working on new project  using s7 -1200 plc 

it consists of 

1 x Cpu 1214C ( DC/DC/DC)

4 x Digital input  module (16 input ) SM 1221 DC

1 x Digital outputs  module (16 o/p) SM 1222 DC.

this my first program with Siemens PLC . I wrote very simple program and  loaded to CPU without errors.

I started to test the online operation but I noticed that all digital I/P inside the CPU and output are connected in ladder diagram are working perfectly.

But all I/P and O/P in expansion modules is not working  also the built-in Led inside the Input =modules is going  On according the input status ; but not changing its symbol in ladder to green .

I tried one rung program using digital input from CPU module and coil output in Digital output module ( just switch and  coil)  and the equivalent   CPU digital input bit LED it On but the output  oin the module is not turning On also in online monitoring the output symbol is going green.

I replace the output module and input module and still facing the same .

please help me..

Hello,

Do I understand it right:

The output is not switching, but in Program iit is 'green'?

Best regards,

Wizard

Hello,

problem can be with addresses of DI I/O, look to PLC HW and check that. Also problem can be not existing power wiring L+ / M for modules. Look to documentation how wire that modules with proper power.

As i understand from your post the output coil in the program is green but physically led is not green.

Are you measure the voltage at that specific input which you trigger in the program.

Because it may be problem of LED in the output module.

But you write in your post that you Replace that module also..

So there must be problem in the hardware configuration. you must see the addressing of the output module, After try to on the output..

AutoGen_855084

I am working on new project  using s7 -1200 plc 

it consists of 

1 x Cpu 1214C ( DC/DC/DC)

4 x Digital input  module (16 input ) SM 1221 DC

1 x Digital outputs  module (16 o/p) SM 1222 DC.

this my first program with Siemens PLC . I wrote very simple program and  loaded to CPU without errors.

I started to test the online operation but I noticed that all digital I/P inside the CPU and output are connected in ladder diagram are working perfectly.

But all I/P and O/P in expansion modules is not working  also the built-in Led inside the Input =modules is going  On according the input status ; but not changing its symbol in ladder to green .

I tried one rung program using digital input from CPU module and coil output in Digital output module ( just switch and  coil)  and the equivalent   CPU digital input bit LED it On but the output  oin the module is not turning On also in online monitoring the output symbol is going green.

I replace the output module and input module and still facing the same .

 

please help me..

 

 Check the output wiring i.e L point & M point and also address of output...!!!

 I think your hardware configuration is missing first add all expansion module through hardware catalog right side of the program. I think you just add one cpu only .any way you make a mistake because this is your first project .

read this book

TIA Portal includes STEP 7 for S7-1200 programming

AutoGen_855084

I am working on new project  using s7 -1200 plc 

it consists of 

1 x Cpu 1214C ( DC/DC/DC)

4 x Digital input  module (16 input ) SM 1221 DC

1 x Digital outputs  module (16 o/p) SM 1222 DC.

this my first program with Siemens PLC . I wrote very simple program and  loaded to CPU without errors.

I started to test the online operation but I noticed that all digital I/P inside the CPU and output are connected in ladder diagram are working perfectly.

But all I/P and O/P in expansion modules is not working  also the built-in Led inside the Input =modules is going  On according the input status ; but not changing its symbol in ladder to green .

I tried one rung program using digital input from CPU module and coil output in Digital output module ( just switch and  coil)  and the equivalent   CPU digital input bit LED it On but the output  oin the module is not turning On also in online monitoring the output symbol is going green.

I replace the output module and input module and still facing the same .

 

please help me..

 

 thanks huggy_d1 I appreciate these following below your points you mentions for every one who beginner or experts. I also recommend as it is. thanks a lot.

huggy_d1

Others have posted all around the problem resolution.  I'll summarize what is supposed to be done when commissioning modules with S7-1200 PLC components:

1. Add modules in PLC devices/modules in TIA Portal that match your physical hardware components.

2. Wire up the L+/M on every device according to their need/use (relay outputs in particular rely upon this the most).  REMEMBER to slide the buss slider between the modules and the PLC.  This is how data is transferred.

3. Wire up I/O.

4. Go online with PLC and compile/download hardware.

5. Write plc logic, compile/download to PLC.

6. Test, repeating any steps as required to achieve happy customer.

New question published by Farzad_Sadr is split to a separate thread with the subject When connect power to the digital input, nothing happens - The corresponding LED lights up but nothing on the output side..

Best regards
Jen_Moderator