crio module wiring help

[CraigAO]

Attempted to start a system up using the cRio-9075 chassis and four c series modules and ran into an issue where I believe we may have damaged the NI 9485 module.

I believe the problem is in the external wiring for the system the cRio was placed in and would like to have someone look over the schematic (attached) and provide any feedback possible before I replace the module. The schematic provided to me was based on the Field Point configuration that this system is replacing.

With the program running, when either ch0 or ch1 is enabled the ethernet connections registers as temporarily disconnected then the program stops working. There is a strong smell of overheated electronics when this occurs.

PS1 in the schematic is an NI PS-15.

[AndyClegg]

In terms of a quick look at wiring, difficult to be definitive since we can't see what is on other end in terms of sensors / pump speed etc - and their data sheets and wiring requirements. My first question would be what is the current draw through the relay when you connect the power supply voltage across them, the 9845 has maximum currents that it can handle (both per channel and for whole module) and it may be that you are exceeding that limit. See manual for those limits.

There's also the possibility that the actual wiring dosen't match the drawing, or there is some fault (short) somewhere, but I presume you have checked that.

[CraigAO]

Thanks for your reply.

We found that the relay socket also had a relay indicator that utilized a diode that was opposite polarity of the wiring causing a direct short. The indicator was another plug in to the socket so wasn't detailed in the socket manual. This was something not indicated in the drawing and we didn't find until we started digging deeper into the hardware.