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View Full Version : Remote IO via ControlNet in Logix5000


TimD
October 4th, 2010, 05:26 PM
Hello,

I have a small controller rack with CPU (L61 ControlLogix) Ethernet (EN2T) and ControlNet (CN2R) module. This system will eventually be redundant.

I have two large I/O racks each with a ControlNet card as well as a about 7 I/O modules per rack. All is connected properly via coax and tees. Node 1, 2 and 3 are all OK on the display of the card.

I successfully set up my CPU rack in Logix5000 but can't seem to add the remote I/O racks. Never tried this before. I am going to read through the ControlNet manual (200+ pages) tonight, but I figured I'd throw this out for someone who has been here before and maybe get a head start.

I thought I'd simply add the additional ControlNet cards under the primary (CPU rack) one, and/or just browse ControlNet right from Logix... but not that simple. I cannot find the 1756-CNBR/C in any list, I find Rev A, B, D and E... is this my problem?

I do have the 7-day grace of RSNetWorx for ControlNet, and have been able to configure my ControlNet easily (no more keeper issues). I am able to view the remote I/O from this application, as well as Linx Classic via USB into my primary ControlNet node (CPU Rack). Diagnostocs says everything is working well, only 1 minor recoverable fault on a DH+ card, I'll get to that later (I guess channel B isn't hooked up and that's why).

I appreciate any help and suggestions. Again, I can browse the entire network via RSLinx and also RSNetWorx for ControlNet... just not able to bring in the I/O into my Logix5000 I/O Configuration.

Thanks!

Ken Roach
October 4th, 2010, 06:21 PM
I/O configuration inside RSLogix 5000 is entirely a manual process. There is no browsing for I/O nodes or modules or connections. You right click on the Parent device and add "New Module", then select your Child module from the available devices.

When I don't know the revisions (or even the actual modules) I enter the newest available revision and plan to possibly have to re-do the I/O configuration later.

When I do have access to a powered-up system, I often find myself switching back and forth between RSLinx Classic and RSLogix 5000 to check the module part numbers and revisions that are actually installed.

You made an interesting comment about 1756-CN2R/B modules (these are the ones with USB connectors) and also about 1756-CNBR/C modules.

A note: Allen-Bradley folks universally refer to the 1756-CNB and 1756-CNBR module together as "1756-CNB(R)". The firmware for the single-media and the dual-media units are identical. Series letters are often appended with a slash, so "1756-CNB(R)/B" refers to either the single or dual media module with Series B hardware and/or firmware.

1756-CN2 are the high-performance versions of the ControlNet modules for ControlLogix.

1756-CN2(R) Series A are essentially orphans; you can't use them as root bridges in Redundancy systems and they were only sold for high-capacity ControlLogix systems. These had ordinary ControlJet Network Access Ports (RJ-45 style) on the front.

1756-CN2(R) Series B are the modern high-performance ControlNet modules with the USB port. They are used both in high-capacity systems and in Enhanced Redundancy systems.

My recollection is that 1756-CNBR/C were the second generation of 1756-CNB / CNBR hardware, and were built only for ProcessLogix systems eight or nine years ago. Are you sure you have 1756-CNBR Series C modules ? What sort of date codes are on them ? Did you buy them new or remove them from service in an older system ?

TimD
October 4th, 2010, 06:35 PM
Hi Ken, I think we're on to something (bad) :(

Yes, these CNBR/C cards are exactly from a previous ProcessLogix system. We are migrating to ControlLogix. We purchased two new CN2R modules for the redundant CPU racks, with the understanding that we could still use the older CNBR/C's in the remote I/O racks.

I read through what I needed to and your advice mirrored what I now understand... add the remote ControlNet under the Primary (Bridge) module and then add the I/O from there. I totally switch from Linx to Logix when I commission as well! :)

Anyway, I get this bad feeling that while my older ControlNet cards can 'talk' in Linx and NetWorx... they are no good for Logix 5000.... I can'[t seem to import the module's .eds file either... I hope I'm not stuck buying two more ControlNet cards. Ouch.

Thanks for the quick reply. Hope what I said makes sense... and perhaps there is a solution other than paying more :(

TimD
October 4th, 2010, 06:43 PM
BTW, I have the newer CN2R/B's for the redundant racks, whew.

Ken Roach
October 4th, 2010, 07:28 PM
Don't panic yet.

My recollection is that the hardware platform for the 1756-CNB(R) Series C is the same as the Series D, which are usable (and popular) as remote rack "adapters" with modern 1756-CN2(R) and Enhanced Redundancy.

I'm going to go ruffle through my memory banks....

Ken Roach
October 4th, 2010, 07:43 PM
Okay, feel free to panic now. I found a detailed 1756-CNB firmware history here at RA Technical Support.

1756-CNB(R) Series C had only the 4.2 and 4.22 firmware releases and are unique hardware. They cannot run Series B nor Series D firmware.

1756-CNB(R) Series D version 5.24 was the first release of 1756-CNB(R) product that supported ControlLogix Redundancy.

I think you're going to have to trade in those Series C modules for new 1756-CNB(R) Series E's. The Step Forward program should help a lot.

TimD
October 4th, 2010, 09:13 PM
Thanks, Ken, very well done.

I'll look into Step Forward asap Tuesday AM.

Thanks for all your help!

Ken Roach
October 6th, 2010, 01:19 PM
Now I'm less sure.... I did some thinking about this and I think that the "Series D version 5.x minimum" applies to the 1756-CNB modules in the rack with the ControlLogix controllers only.

The "adapter" mode... those might work. There's no minimum version for the 1794-ACNR or 1771-ACNR, for example, to work with Redundancy (other than the fact that they have to run ControlNet 1.5).

I think you're going to have to arrange a test to see if these will work. I would put them in the project as Series B and try Compatible Keying first, then try Disabled keying.

Officially, the 1756-CNB/C was only for ProcessLogix. ProcessLogix was also an unscheduled-only system so it's possible the 1756-CNB/C won't correctly accept a scheduled connection from a 1756-CN2/B.