Richard Kowalczyk 3 years ago in Expansion modules / XC10 updated by Gustav Widén (System support) 3 years ago 2

Hi everyone,

I have been working on a quite complex system. When using XC10 all relay coils (or valve solenoids) controlled by DOUT(LS) have been powered from +BAT and it has been working fine. However checking program, for no reason, have found in the the Instruction book that one or more DOUT should be used to power these coils or solenoids. Is there any risk with what I am doing ? I have checked that for MC43 and MD4, that I have been using on the same system, it is allowed to use +BAT for power. I can of course do it by book but the program would become a little bit awkward and messy.

Any comments will be much appreciated

Richard Kowalczyk

RKad Engineering


In the XC10 instruction book

Image 2472

The risk is unintended movement if the wires are shorted to ground. 

Both short to a plus and a short to ground can happen in the wiring harness, for example the insulation on the cable is abraded. But a short to ground is in general more likely, for example an abraded cable touching a chassis part. 

What sets the XC10 apart is that it has low side outputs rated to currents that make it possible to drive coils on hydraulic valves directly.

On e.g. the MD4 you have low current low side outputs that can be used for small loads like buzzers, but not for coils on hydraulic valves.

Note that for any design where you need to prove the safety integrity of a function, you select an MC4xFS and output combinations that control coils on both highside and lowside.