hello,

I do have configuration of 1200 CPU and two 16DI/16DQ modules. The last one module is connected through bus extension cable (6ES7290-6AA30-0XA0).

The second one module green DIAG LED is blinking. And I cant read/write signals. Inputs work (I can see green leds on module lightning when pressing buttons for example). Howevere the signal doesn't pass throu to CPU. Ditto for outputs (I set output but no green led light on module - no output signal).

Module green diag led blinking means "Not configured / Update in process". What am I doing wrong ?

Software use "dynamic" hw configuration. Operator picks one of the hardware configurations and restart machine. Software use WRREC to send some data (different for different hw configuration) to system rack slots. I don't fully understand the process but I think the selected configuration should be related to real presented hw. If not the operation WRREC reports error. If no error the new selected hw configuration coud be used. Am I right? Where can I get more information concerning such a "dynamic hw config" ?

The second 16DI/16DQ module is new and I suppose I should correct HW configurations for WRREC operation. Am I right?

Could this be a source of problem? 

(Note: I'm not author of code. Its a heritage from my predecessor.)

Hello,

First if you can show us your hardware configuration, we will se maybe something wrong.

If you can't, check your configured hardware in TIA portal and existing modules or they match, to see what hardware you use open module cover and see it's number like this 223-1BL32-0XB0

and these modules must be inserted to correct slots and configured in TIA portal, then you need rebuild hardware and download to PLC.

hello,

I've minimalized the project and hardware configuration:

1. - S7 1200 CPU

2. - 1x 16DI/16DQ

(variant - 2->3 bus extension cable)

3. - 1x 16DI/16DQ

2nd and 3rd modules connected directly OR connected by bus extension cable.

Both DI/DQ modules was switched in between for tests.

Simple empty project (no Configuration control !). Only writing TRUE to some outputs of DI/DQ modules.

The second DI/DQ module always doesn't work (output is not set) and its DIAG green LED blinks. Its the same for all four variants (with/without extension cable; switched modules).

Project and photo of hardware enclosed...

Hello.

The concept you need to look at is "configuration control" or "option handling" of "standard machines". There may be some issue with how the PLC was configured or how the option card is being selected.

Theoretical background is listed in the System Manual of the S7-1200 as well as some postings on the Siemens support site. An old posting is quoted below:

ChristophD

Hi,

Confugration Control (Option Handling) mean that you can configure the I/O Modules in the PLC Rack, so that not all projected modules must be present.

Here are 2 FAQ's for this functionality:

https://support.industry.siemens.com/cs/ww/en/view/29430270

https://support.industry.siemens.com/cs/ww/en/view/109481852

Regards
Christoph

hello, thanks for links to the Configuration Control. 

I have focused the problem in meantime so Conf.Control doesn't have anything with it. See my post above.... 

I have REMOVED Configuration Control. I have tested only FIXED configuration: CPU + 2x 16DI/DQ. Empty project. The problem still persist,

So Configuration Control isn't problem more !!!!

Why the second DI/DQ module doesn't work even in fixed configuration ???

2.question: "it does require the modules are present in the base hardware configuration before they can be "optioned" out of the project's hardware." Really ??? I didn't find anything about it in Simatic help.

Problem solved. Thanks to all for your help !!!

It was something with Downloading HW configuration. It wasn't done correctly first time probably. When downloading again (in offline !!!) system starts to behave normally and the second module works.