DeviceNet to Hardwire control

[Mr JJ 0]

We have a customer that has two VF drives controlled by DeviceNet (1747-SDN & SLC504). They want to control this VF now by a start and stop PB's. They dont want to get rid of the DeviceNet for fear they may need it for the furture and for validation purposes. What is the best way to approach this. They turn it on/off by a HMI. They say there are too many steps going through the HMI. I've never done anything with DeviceNet. All I have is RSlogix500. Will I need Networks? Thanks in advance for any help provided. John

[jimdi4 2]

Yep, RSNetworx for DeviceNet...You have to configure the DeviceNet network with it... Edited 27 Nov 2007 by jimdi4

[Eddie Willers 2]

I don't think you necessarily need to change the DeviceNet configuration. You probably just need to stop sending start/stop commands from the SLC-5/04 controller and change some of the control configuration parameters in the drive. What model of variable frequency drives are these ?

[leonuce 0]

Just desconnect the DeviceNet and reprogram you controller with the addition of the PB's. Youn can also control the VF Drives using limit switches or sensors depending on the process to be controlled.

[bguinn 0]

I don't know which drive you are using, but most of the drives I have used want to know where the commands, and references are coming from. Whether it be from the terminals, the keypad, or a comm port. All you should have to do is change the drive command bits to come from the terminal strip instead of the comm port. This should cause the drive to only run from the start/stop pushbuttons. This would not require any network changes I don't believe. OR, You could wire the start stop buttons to the PLC, and still have the comm port controling the command and reference. This would only require some minor PLC changes. Depending on how it is written, you could still leave the HMI buttons active also. Hope these options help, or make sense