Replacing Powerflex 575 devicenet VFD with different VFD

[khekd]

Hello all,

It's been a while but have an odd request.

Have a customer that has a AB SLC5/05 with a SDN module. On the network are several Powerflex 575 VFDs. Customer wants to replace with a different VFD.

Here's the rub...they want to use a Siemens VFD but the G120 doesn't have Devicenet. I did find a Devicenet slave to Profinet master gateway. That way the gateway can act as the Devicenet slave in lue of the VFD. Then the profinet master can control the new Siemens VFD.

The customer cannot get the source code and the RSnetworks DNet config. I believe the IO image of the Powerflex 575 is 128 I/O by default. DInt for control/status and DInt for speed control/ref. This would not be an issue to map it to the profinet side. My biggest concern is making the SDN think that the DN/PN gateway is the VFD. Does the SDN look at the device type ID or just the I/O size and type?

I know this is a crazy ask but wanna see if anyone has tried anything like this before. TIA for any feedback?

 

[alan_505]

I am fairly sure that it will look at the device, so if you put a different device the DeviceNet scanner will throw a fault with product mismatch.

What is a 575 is that a new drive from Allan Bradley, I assume you mean PowerFlex 525?

 

[Ken Roach]

Welcome to the PLCTalk forum community !

I don't think this is a good plan, when PowerFlex are widely available in Indiana, but if your client has the money to pay you for your time, they can make their own decisions.

There is no chance that you can do it without access to the PLC program and the DeviceNet configuration.

You could very probably make this work with a DeviceNet Slave/ Profibus DP Master converter. I'd probably use an NT50 from Hilscher.

Swapping one brand of VFD for another is possible with DeviceNet if the drives all use the same ODVA profile (though most VFD makers have a Vendor Specific profile by default).

But between a PowerFlex 525 and a G120, the data map is probably going to be a different size, and will surely have different meanings for the command and feedback data bits and values. You need to figure out how that Profibus data is going to look in the SLC-5/05 I/O table once you map the gateway into the scanner.

>Does the SDN look at the device type ID or just the I/O size and type?

Electronic Keying can be set to as strict as the firmware minor revision, or as generic as nothing at all, so just Connection Type and Input/Output Sizes.

Most VFDs on DeviceNet are set for at least Vendor and Device Type keying.

>cannot get the source code

Are they locked out of the PLC program, or are they just not providing you with the information you need ?

This would be very, very difficult to do without access to edit the PLC program, even with expert DeviceNet and Profibus experience. I have never done a network gateway where I had to re-map the bits in a command or status byte, or swap bytes and scale units between the two sides.

Maybe a Hilscher NT100 with LuaScript could do that.

 

[khekd]

Thx guys for the replies.

This source code belongs to the OEM and is not provided to the end user. I guess I will have to try to hack through it or punt.