64 words - PanelBuilder32

Hi everyone,

Here's what I'm using:

ControlLogix5000
PanelBuilder32
PanelView rev. 4.2
DeviceNet

I am sending text, FLOAT, and DINT from the PLC to the Panel View to display messages and other data from the machine. All this information adds up to more than 64 words needed to be displayed at the same time. In the communication settings of PanelBuilder I can set it to a max of 64 words. I wanted to know if this was a limitation of

- PanelBuilder32
- PanelView
- DeviceNet

According to their tech support it's a max of 64 words and nothing can be done. This is not very much if your application is medium to large size.

Also, I'm familiar with multiplexing data (reusing the same memory blocks for different screens) but it still doesn't solve my problem.

If anyone knows anything about this, it would be appreciated!

Thanks alot!

Claude

It's a limitation of the PanelView.

Ordinarily, DeviceNet permits I/O connections of up to 255 bytes. But the PanelView's heritage is from the Remote I/O network, where the biggest I/O memory block (i.e. a Block Transfer) is 64 Words. My best guess is that the PanelView designers when told to create a DeviceNet interface decided not to change the part of the firmware that deals with I/O blocks.

I agree that DeviceNet is not the right network for PanelView applications above a few screens. It's brilliant when you want to use direct explicit messaging to devices, but I seldom recommend a unit bigger than the PV600 on DeviceNet.

The being said, the good news is that it's relatively easy to increase the amount of I/O transferred between the PV and the ControlLogix.

What you have set up now is DeviceNet data Assemblies 1 and 2 for Input and Output data. Those are automatically being exchanged with the I/O memory map of the 1756-DNB via the I/O connection you set up with RSNetworx for DeviceNet.

There are actually 16 available Assemblies in the PanelView, so you can use MSG instructions in the ControlLogix to read and write those assemblies.

Go into PanelBuilder Help and use the keyword "Explicit" to pull up "Explicit Server". You'll find a tab in the Tag Editor that brings up the tags assigned to Explicit Server memory separately from the I/O Slave memory.

I don't have a lot of application experience in this, but I think I can help get you started. The hard part now is going to be addressing the I:xx and O:xx addresses inside PanelBuilder and making sure they match the offset you intend in the MSG block being sent to the PanelView.

Remember also that the PanelView can only handle 4 explicit message connections at a time. If you're sending more than one set of read/write messages, make sure you uncache the message and allow time for the PV and the controller to establish their connection; this can be a few hundred milliseconds.

I usually put all of my pushbuttons and digital indicators in the I/O assembly, then put the integer and floating-point data into a slower update mechanism like explicit messaging. The good news is that it's easy to do explicit messages in ControlLogix, wheras it's a monster in SLC and PLC-5.

FYI:

I had a similar problem with a Panelview 1400e, a SLC 5/05, and Remote I/O. I found that I could transfer more by creating more I/O racks in the Panelview. I'm writing 64 integers to the Panelview and reading back 64 integers. So, my Panelview takes up two racks. I might be going about that wrong, but as long as it works I don't want to poke at it!

One other unexpected behavior that I noticed was that the block transfer commands were changing by themselves in my ladder logic. I'd get comm fails and find out that the rack address and byte count in the BTR or BTW instruction had changed. I suspect that this problem was due to the fact that my control bytes were in the same memory file as my data. I think that the control data was being overwritten on the read cycle, but nothing in the manuals could prove that to me. And, I'd put enough space between memory locations that I thought I'd be safe. When I moved my control bytes to a new integer file, the problem went away.

AK

I read up on the control net panelview thing because we were gonna use one on a control net. But I thought the 64 words was a limitation of a scheduled data transfer. I think you just configure a tag to write to a data table and the controlnet will pass the data in an unscheduled transfer--or maybe that was only to a PLC-5-C data table--because I don't think you can write to a controllogix data table in an unscheduled manner--because the controllogix processor is the only one who knows how it's data table is configured--I'm confused, now--hope you're not.

Ken,

Thanks for the info. I am now able to pass all the info I want using the extra assemblies.

John,

According to the AB tech support DeviceNet is the 64 words limitation but if you use ControlNet, there is no limit on the amount of data (words) that can be passed between Logix5000 and PanelView.

Thanks for your quick replies. Appreciated!

Claude

Yea, you did specify device-net, didn't you? Sometimes I look but I do not see!