PanelView Plus Comms

We've got a job in Idaho, with a SLC 5/04 as the master PLC. One port on the SLC is using DH-485 to communicate to two SLC 5/03s, six ML-1200s, and seven PanelView 550s. The other port on the master SLC is configured as DH+, and is communicating with a Panelview Plus.

So far so good. The owner wants to tie his SCADA system into the DH+ link. We configured the PanelView and the SLC so there are no address conflicts, and the SCADA integrator can find both devices from his lapto using an AB DH+ card.

The SCADA PC is only connected to a few SLCs and a PC with a Wonderware package. As soon as our panel is connected to the rest of the network, the whole DH+ network crashes. I think the PanelView Plus is throwing so many transactions on the network that nobody else can communicate with it.

WE know from another project that is we put the Panelview Plus on the DH-485 network, that network will crash.

Any ideas, suggestions, questions, new cuss words ............

... stories like these is making me sweat, I'm about to put a PV1200+ on the plant's ethernet ... I'm scared utoh

So I assume you already tested with just the SLC on the network, right? What's the firmware situation? AB seems to suggest there is a DH+ problem with PV600+ on one of their KB. DH+ speed, termination match? That's all i can think of for now.

more info

Just to add... I'm working with Tom Jenkins on this problem. When the system integrator plugged in his SCADA system to our DH+ network. The entire DH+ network went down. When he removed our SLC 5/04 from the network, the network remained down. When he plugged the SLC 5/04 back in, but unplugged the Panelview + his network came back up instantly. From what I've seen, the Panelview + is a communication hog. I have the refresh and update rate turned down about as slow as possible on the Panelview Plus, but it seems to make no difference.

from the "long shot" department ...

I’m SURE that you guys have thought of this ... so no offense intended ... but as for the DH+ cabling ... there aren’t any “star” connections involved in the "blue-hose" wiring are there? ... specifically, each connector should have only one cable coming “in” and only one cable going “out” (except for the end connectors of course) ... as you know, three (or more) cables in one connector is a big “no-no” ... also check the terminating resistors on the bitter ends ...

I’ve seen cases before where the guy “in charge” knew all of the rules but the “screwdriver” guy running the cables messed up - and then hid the mess in the Panduit ... sometimes it helps to double-check the obvious ... good luck ...

Actually, Ron, that is a great question. We didn't supply the DH+ comm wiring or the SCADA equipment, all of which is located in a different building. The system integrator is experienced, but the electrician wasn't.

The rest of the system works OK without the PanelView Plus connected, so I suspect that wiring is not the problem. Nonetheless, I'll pass this inquiry on to the integrator.

The 2711P-RN6 module's wire assignments are *backwards* from ordinary SLC-5/04 DH+ ports and the ones on PanelView Standard terminals. This is true of any device that is based on the 1784-PKTX card, including the PanelView Enhanced and of course the 1784-PKTX itself.

If the SLC-5/04's all have the Clear wire on Terminal 1, for example, the PV+ should have the Clear wire on Terminal 2.

This doesn't explain why the one SLC-5/04 and the PV+ work correctly together, so I'm still scratching my head. It also only applies to the PV+ 700-1500 terminals. I'm not familiar with the DH+ daughterboard for the PV+ 400/600 terminals.

I am not entirely confident in the behavior of the PV+ as far as DH+ traffic goes, but I am still looking for an opportunity to put one onto a working network and run my DH+ traffic analyzer.

(Where in Idaho is the project ? I'm in Spokane this week .)

My network consists of a 5/04, a PLC-5/80E, a CLX DHRIO module (Chan A), a DH+ standard PanelView, a DH+ PV+ 1250, and 2 PC's w/PKTX cards. We have not experienced this phemomenon, except when I inadvertently reversed the blue and clear wires for the PV+. It didn't bring down my whole network, but is sure brought the 5/04 (which connected directly to the PV+) to a screeching halt.

We've got a job in Idaho, with a SLC 5/04 as the master PLC. One port on the SLC is using DH-485 to communicate to two SLC 5/03s, six ML-1200s, and seven PanelView 550s. The other port on the master SLC is configured as DH+, and is communicating with a Panelview Plus.

Click to expand...

I am not clear on this. To my knowledge the SLC 5/04 has
one DH+ port and one RS-232 port. Are you saying that the RS-232
port has been equipped with the AIC+ converter and all other PLC's
(5/03's and ML-1200's) are all also equipped with the AIC+ to convert RS-232 to RS-485?

WE know from another project that is we put the Panelview Plus on the DH-485 network, that network will crash.

Click to expand...

I thought that the PanelView Plus is on the DH+? Are you saying that the PanelView Plus is a bandwidth hog no matter what network?

This doesn't explain why the one SLC-5/04 and the PV+ work correctly together, so I'm still scratching my head.

Click to expand...

Well if both ends ( SLC and PV+) are wired in reverse then they will work OK but when connected to the SCADA which follows the wiring standards the DH+ would crash.

In order to minimize the traffic, the data to / from PV+ should be
in contiguous files.
Make sure that your DH+ is wired properly, i.e. if you are using
T drops you need to have capacitor installed. Also there is a limit on the length of the drop. For T drops AB has a box they call Station Connector, an overpriced Hoffman box with resistor and a capacitor. The safest way is to route it all in a daisy chain.

Tom I recall reading an article on knowledgebase concerning the SLC 504 crashing with too much traffic I've been trying to find that article but thus far haven't met with sucess.

Re: more info

hilgs said:

From what I've seen, the Panelview + is a communication hog.

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I think you're right about that, Tim. I've seen communication lag severely with networked Panelviews. They all want to be in charge. But, I haven't seen the network take a complete dive like that unless there was something wrong in the wiring or hardware. Do you know how many nodes are on the SCADA network? How many of those are actively polling for data?

For your back pocket: DH+ is essentially an RS-485 connection (I've been told), you might consider checking your line voltages to see if they're up to snuff.


Harryting should do better on ethernet, though. Switches tend to help with data traffic.

Can someone explain what's special about the Panelview Plus terminals? How are they different from the standard PV? Aren't they the ones that require RSViewME for screen design?

AK

Jiri: The DB9 port on the 5/04 can be set to DH485 OR DF1, I am quite sure.

Tom/Hilgs: So can I assume you are not onsite and haven't inspect the DH+ wiring yourself?

What the others said about reversing the blue/clear pair make sense until I read the part about the network working with just the SLC but not with the PV+. How's thing looking in RSlinx

here is one article I've found on PV plus
http://domino.automation.rockwell.com/applications/kb/RAKB.nsf/0/55297DE621E0C10785256D64005C165E?OpenDocument

Apparently the connections are backwards to the standard DH+ connectiopns

Re: Re: more info

akreel said:

Can someone explain what's special about the Panelview Plus terminals? How are they different from the standard PV? Aren't they the ones that require RSViewME for screen design?

AK

Click to expand...

PV+ are heaps different... Yes, they require RSView for their screen design.. Their hardware is different - made up of different modules, such that the screen is a separate module to the processor, etc.

Heaps more colours & better resolution too!

This line set off a red flag.

Tom Jenkins said:

...the DH+ comm wiring or the SCADA equipment, all of which is located in a different building.

Click to expand...

I don't have any specs on me. But just how far away is this "different building"? I've lost DH+ when severely exceeding the distance spec.

"But Mr. Engineer, it's only connected to the device on the other side of this wall"
"Yes, Mr. Customer, but the cable is going along the wall, through the ceiling, around the mezzanine.... AND you are trying to run it at 230 baud."

I won't pretend to be the expert on this one.

My somewhat educated guesses have been already adressed, and are:

Swapped network with TOO much date

Star Wiring, with TOO much load, pulling data level (voltage) down

Ubgodly loss do to length and capacitive coupling or high noise factor

Best I can say is good luck.....casey