Wiring of DeviceNet on Kuka

[Mech_t]

Hey guys,

I faced a problem recently. I am using KRC2 (for robot KR16). I hooked up some solenoid valve onto the DeviceNet previously. There was no problem and everything was working just fine. Recently I wanted to attach some sensors to it.
I got myself a fiber sensor & limit switch. I was told by the Kuka guys that the DeviceNet can only support a PNP sensor. NPN sensor needs an additional relay to be connected.

Well, I followed their instruction and wired a PNP fiber sensor to the DeviceNet Input according to the instruction from the sensor suppliers.

On the 3rd day, after wiring and using it, the fuse that is attached to the PLC input (24VDC) burnt. I was told by the kuka guys, that this is due to the wiring problem. There are some short circuit in my wiring. I checked back my wiring, but could not identify any problem in it.

Can anyone, help me out here. I would like to find out my could be the possible cause for the fuse to burn. I don't want to continuously keep burning the fuse or even worse, create bigger damage to the controller (KRC2)

I believe the max current output for the DeviceNet is 2amps. The sensors were only using 0.4Amps.

My understanding is, If the wiring is wrong then the sensor's won't function in the 1st place. Pls help me out here.
I thank you in advance for your help.

[MartinH]

Not a solution, but a suggestion.

We use DeviceNet on our KR16, but as I understand it, we dont use it in the way it was intended.  We only use the DeviceNet power to run the DeviceNet modules, and we use a separate 24V to power the solenoids and sensors.  To date, we havent blown any fuses.

I dont have the wiring diagrams to hand, but from memory, it's the 4A 24V DC on connector X11 (??) in the KRC2 that we use.  You could try doing it this way if you can, to find out whether you blow a 4A fuse.

[Mech_t]

The fuse that was burnt was the F22 (I believe it is a 2Amp fuse).
Can you share your experience on how you wire the sensors to your robot?

Thanks Martin.

[MartinH]

We use a Beckhoff BK5200 - http://www.beckhoff.com/english/busterm/bk5200.htm

Wire 24V DC power supply from terminal 36 on X11 to the Beckhoff module labelled "24V", and also 0V from terminal 18 on X11 labelled "0V".  You then have to supply your choice of sensor voltage (24V DC, 240V AC etc) to Beckhoff terminals "+" and "-".  We wanted 24V DC, so link from "24V" to "+", and "0V" to "-".

Add Beckhoff input / output modules as required (eg 4 input module KL1104), and add an end terminal KL9010.

Set node address using DIP switches.  Configure KRC2.  Connect the DeviceNet cable.  Done!

(Note - no Beckhoff software required)