DeviceNet Issue

Hi Guys,

I need some suggestions for this project.

I am limited to One 1756-DNB DeviceNet Scanner. I require to Map 210 DWords of Data. The 1756-DNB Only allows 126 DWords. What are my options? I cannot add another DeviceNet work. Can I have another scanner on same network perhaps?

Set up the DeviceNet slaves to alternate between two sets of data and include a word or bit to indicate which of the two sets they are providing. If your scanner is also writing to the slaves, it can include a bit or word to tell them when to switch detween data sets.

sort of

you can put another DNB card onto the network, but it has to be in slave mode
That's a ton of data 210 DINTs!

Do you really need to poll all of the data all of the time? You may be able to use explicit messages for some devices to free up memory in the scanner.

Andybr.

You can install multiple scanners on a DeviceNet, but the network settings need to allow enough bandwidth for them to both function. In my experience this means either using Change-Of-State of slow Cyclic data connections, or setting high Interscan Delay values so that there's enough "quiet time" between poll cycles for all the replies to get through.

How many slave devices, and of what type, are you planning to use ?

I would do as Andybr - explicit messages all the way.

If you have 210DWords for sure a lot of them will come just from one source, you might need just a couple of extra explicits