Communication loss ab7000


#1

Hi,

We currently use Anybus Communicator AB7000 with a Climet Device. We observed very rarely loss of communication. The installation is done with a DeviceNet Allen Bradley THin Cable 1485C-PI-C. The pins 8 and 9 are used for the communication of the Converter. Signal ground is done trough the cable shielding (Pin #5 is not used on the converter).

Could you confirm that the cable AllenBradley is the good one for this application ?
Also, could you confirm that the signal grounding is ok the way it’s done ?


We want to be sure first that the wiring is done properly.

Best regards


#2

Hi @phlac,

I would like to point out that the port on the bottom is the serail port either RS485/422/232. Using a profibus cable would be fine for the most part here but DeviceNet is done over a CAN bus so the cable usually have termination. This could be causing issues on the RS485 connection you are making. Just looking at the image of the communicator you can see the switch for turning on and off the CAN termination.

Take a look at the diagram on page 71 of the user guide for rs485 wiring. There are different termination used the CAN while they are recommended it is not always necessary for rs485.

Deryck