Configuring DeviceNet Devices

[holomorph]

I've got a PCI-DNET card and am planning to use labview to control devices on my DeviceNet network. My issue is in configuring the devices I have attached. I'm wondering how other people using this card are configuring thier devices?

The product spec sheet says the card is compatible with Allen-Bradley DeviceNetManager software, but unfortunately it appears to be obsolete, having been (as far as I can tell) replaced by a new piece of software called RsNetWorx. After talking with NI support, they inform me that the drivers for the card only support 16 bit applications (which DeviceNetManager was), but RsNetWorks is 32 bit, so it looks like that won't work.

Does everyone just use the NI-DNET api to configure the devices on their network, or am I completely missing something here?

- Bjorn

[frankwu]

You can use SimpleWho provided in MAX as a good start.

It can help you to browse all the devices connected to the bus and get each device's basic information, such as type, IO length and so on.

LabVIEW's NI-DNET examples show how to configure the devices by the explicit message and IO scan.

[holomorph]

Yes, using SimpleWho and getting labview to connect with the device was easy. The problem was in setting parameters; for instance configuring IO points for one of my devices, was not obvious. Since the software that came with the card had no ability to read and interpret an eds file, then configure parameters based on the information in that file, and the hardware manufactuers expect that was how people would be configuring devices, I was pretty lost as to which messages to send to the device in order to configure the more device specific stuff. I finally did get some information on the eds file format from someone at Allen-Bradley, and was then able to understand the eds file enough to write a labview program which sets the correct attributes.

In case anyone else is having as similar problem, here's what they said:

first I would reference a Knowledgebase record that describes Explicit
Messaging; G16551 - DeviceNet Basics of Explicit Messaging. Knowledgebase is a database of application notes and technical
information on Rockwell products. A link for Knowledgebase can be found
on the Rockwell Support website: http://support.rockwellautomation.com

The following is an excerpt of an EDS file for an AB 160 drive which
happens to be commented to include information on the different entries.
Be aware that not all parameters can be written too but most if not all
parameters can be read.

Param30= $ parameter instance
0, $ data slot - don't care
6, "20 2A 24 01 30 69", $ path size, logical address
(class, instance, attribute)
0x0030, $ descriptor - in hex format
2, $ data type (UINT)
2, $ data size
"Bus Voltage", $ name
"V", $ units
"", $ user manual reference page
0, 800, 0, $ min, max, default data values
1, 1, 1, 0, $ mult, div, base, offset scaling
0, 0, 0, 0, $ mult, div, base, offset links
not used
0; $ decimal places

As you can see in the comments the line: 6, "20 2A 24 01 30 69";
is the path of the parameter which includes the Class, Instance, and
Attribute information which is necessary for the explicit message.

To read this parameter one would use the get attribute single command 0x0e
with Class 0x2A instance 0x01 attribute 0x69

I also atached my little program to get and set attributes.

[holomorph]

oops, attached now I hope

[frankwu]

Thank holomorph for the wonderful desciption of working with EDS.

[holomorph]

no problem, it caused me enough of a headache I didn't want other people to have to go through the same thing.