Pegaia

Hi,

sorry, but I don't understand 100% your message.
You have a 4..20mA signal. ok

Where you use it (S7-1200 CPU, 331-7KF01,?)

When you receive 4mA what you wolud like to read in your program?
When you receive 204mA what you wolud like to read in your program?

 Hi,

I have a problem related to analog input in my system.

In my project I am using siemens S7-1200 PLC (CPU 1214C AC/DC/Rly) With an Analog Input/out module (SM 1234 AI4/AQ2).

I am using one of the analog Input for taking weighting value (4-20mA) from a Module; Brand: SEWHA, Model: SI 4100; Normally the module is showing actual weighting result (Say if I put one Kilogram over the load cell its showing 1 kilogram) if I dont connect the analog out (from the weighting) to the PLC's analog input. But if I connect with the PLC then weighting modules Indicator as well as HMI (Connected with the PLC) is showing 5 Kilograms, sometimes 10 kilograms also sometimes correct result 1 Kilogram.

I have checked the Weighting module connected with other PLC (LS), its working fine.

I have checked with a new analog card but the result is still the same problematic. 

Hence I will be highly pleased if you suggest me what can do to solve the problem? What can I check?

Thanks in advance.

Regards

Talash

Maintenance Engineer (Automation)

Dhaka, Bangladesh

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Split from SCALE and UNSCALE.

Yes; I have also monitored the analog input value IW96 & it is also oscilating.

For shield: Its a shielded cable & it is separated from the power cable.

I am using MD51

For your last suggestion, Sorry I haven't yet check.

But still facing the problem.

Could you please suggest me anything more ?

Thanks in advance

Talash

Dear Talash,

it's hard to say if this is a hardware or software error without the actual program, can you share your code?

In the meanwhile ask yourself following questions:
-Is the signal steady? Do you have noise?
-Is the input signal correctly according to the weight?
-If the signal is signal and the value is correct at the input, if that's the case, ask yourself... is your hardware confuigration set up correctly? Are your analog input ranges set up correctly? Is your meadumrent type set up correctly?

Tell me if this helped you any further.

Kind regards,
Jens