Open Load Error when MD4 Output turns off

Ethan Zeman 7 years ago updated by Gustav Widén (System support) 7 years ago 4

I am trying to control a relay with an MD4 output (relay turns on a light when certain conditions are met).

When the IDC channel that controls the DOUT channel goes to false (output turns off) the MD4 is displaying an OPEN LOAD error.

We are running IQAN Design 4.07 on this unit.

Any recommendations?

Satisfaction mark by Ethan Zeman 7 years ago
Under review

The IQAN-MD4 DOUT function for detecting open load works in the state when the output is off. 

The MD4 DOUT:s are low-side drivers, and to detect open load they measure voltage on the pin. When there is a load connected there should be a voltage on the pin, if this voltage is to low it will be seen as an open load.  

What voltage level do you supply the relay coils with? 

Thanks for the feedback.

The voltage supply is 24 volts. 

I will have the technicians double check the wiring connections. 

After double checking the wiring it was found that the MD4- DOUT signal was going into the (86) pin of the relay instead of the (85) pin.  After rewiring at the relay the problem is reportedly resolved.  Thanks for the support.


Thanks, good to hear that you solved it.