- I use current transducer Lumel type P11Z-09311008 , it converts 0-5 A input to 4-20 ma output and it actually do it correctly and accurate

- but when i connect it to analogue input module Siemens Type 6ES7331-7KF02-0AB0 it gives like open loop circuit (no reading) i do not know why , note that the input resistance of channel is 25 ohm which in the range of transducer Ro= 0-500 ohm

- we tested another transducer from another supplier on the same analogue module 6ES7331-7KF02-0AB0 and it worked correctly , the only difference i noticed is that Lumel P11Z gives output 4-20 ma on 15 volt DC , but the other transducer gives 4-20 ma on 24 volt DC , does the output voltage of transducer affect on channel reading although the MA reading is correct  ,,, and how i can solve this problem

i wish you can help me as soon as possible

thank you

 Hello Mohamed,

MohamedSerry

- we tested another transducer from another supplier on the same analogue module 6ES7331-7KF02-0AB0 and it worked correctly

 Is it the same module or the same channel?

Are you sure all M- (0VDC) pins of all 4-wire channels are connected together with Mana of the module?

Best regards,

H-H

Hello Mohamed,

I still don't think the 15 Volts would affect your measurement as much as the common mode voltage would do.

You still haven't answered my question.

Are you sure all M- (0VDC) pins of all 4-wire channels are connected together with Mana of the module?

I think this might be the problem.

If the problem persists even after connecting all 0VD wires of 4-wire transmitter together, you can use a resistance to convert the mA to voltage signal that you can connect it to your analog input module.

Best regards,

H-H