Device Net accessories

Hi

I am considering the possibility of implementing a DeviceNet Network from a ControlLogix Processor to integrate a bunch of DeviceNet instruments and weighing systems.

Will it be mandatory to install a DeviceNet power supply and Power Taps? I am not familiar with this network and I wonder if it does get powered up from the controller´s DeviceNet interface.

please advice!

Thank you

Devicenet requires some design and planning.
You dont necessarily need power taps, but you will need a power supply.
Most of the devicenet I have worked on did not require any power taps, but again depends on number of devices and distance between them and your control panel.

I would advise to that you connectorize everything, try not to hardwire anything( just leaves room for problems).

Reply

The DeviceNet card does not power your network devices, just your communications. To power your devices you would need to purchase a 24VDC power supply and connect it to your V+ (24V Red Wire) and V- (0V white wire). Make sure you do the power calculations for your devices on the network because AB maintains that the trunk cables are rated at a max of 4A. If your Max current for the network is greater than 4A you would have to install Bus power tap and re-introduce power.

Hope this Helps

hi

The 24V dc goes to the RED and BLACK wires surely. The benefit of a power tap is that the devicenet network is fused and earthed correctly.The power feed and earth are supplied to the tap.
The rating of the thick cable is eight amps and not four. You have not given any distances so no idea what type of cable to suggest. Make certain that a seperate dedicated psu is used for the network and do not penny pinch and use the control voltage, it may work, but you are asking for trouble in the long run


regards

kevin

There's an indispensable reference for DeviceNet cable systems, called the DeviceNet Cable System Planning and Installation Manual. It's available from A-B as Publication DN-6.7.2.

It's fairly dry and uninteresting reading, though, so a staggering number of first-time DeviceNet users fail to read it. In that way, it's a lot like Moby Dick.

If you only read one page of that manual, make it page 1-17, the Installation Checklist.

Thanks to all of you... I will closely follow your advice. Right now distances between Controller and weighing systems are from 30 to 50 meters. Any suggestions on cable diameters?

Thanks alot (again).