Getting data from PLC5 to CLX - RIO, DH+, Ethernet ????

Hey fellas, I did a search but didn't find anything that quite fit. I'm setting up a new CLX chassis (with processor) for a new project. I need to get some data from a PLC5. It'll be a half dozen words at most. I'm debating what the best method would be.

PLC5 (Enhanced 5/40 Ser C Rev G) is connected to both DH+ and RIO networks. It's the RIO scanner (115k). The DH+ network (57k) is connected to other PLC5s and another CLX chassis with DHRIO and ENBT modules. We use this as a programming bridge (Ethernet to DH+) for our PLC5s.

The new CLX chassis will have an ENBT module for programming and HMI access, and (I'm thinking) either 1756-DHRIO or 1756-RIO module for the comms with the 5.

Options as I see them right now:
1 - Use the RIO module and make it a remote rack of the 5.
2 - Use the DHRIO module connected to the DH+ network and use MSGs to read/write between the CLX and 5.
3 - Use Ethernet and the existing DH+ bridge.

The new CLX chassis is being installed very near the PLC5, so cabling between the two will not be a problem.

Any other ways that I'm not aware of? What would you recommend and why? Your input would be greatly appreciated.

I would use the 1756-DHRIO module over the 1756-RIO module. I am currently working on a project with RIO module and it works best as the RIO scanner instead of adapter. If you are just moving data use DH+ or a 1785-enet side care and message the data back and forth. The RIO module makes you have another file and use a configuration program to configure the module. It is all somewhat integrated into RS 5000 but not there just yet. In your application, you would set the RIO module up as an adapter and do a block transfer to move the data. That is where I am at right now.

I would use DH+

(but then i am bit of a DH+ whore :/ )

Hey fellas,

I've got an update. I've been able to set up the comms as suggested, through and existing CLX bridge, so...

NewCLX > Ethernet >Existing Bridge > DH+ > PLC5

I set up the write and read in the CLX so that the write is triggered by a timer .dn, then the read goes on the write.dn. For now the timer .pre is set to well beyond what the write/read takes just for testing I watched it for about 20 minutes. No errors. I find that a complete write/read takes a little over 1/2 second (64 intg words each way). Lowering the number of words does not seem to make it much faster, maybe a little. The speed is ok for now, but I did give it a challenge. This bridge is the same we use for programming. It's connected to all of our 8 PLC5s. I intentionally uploaded from both the target PLC5 and another to RSL5. The write/read cycle slowed down a lot during the upload form the target. It peaked a few times around 2 seconds. Not sure if I like that. It only slowed a little when uploading from one of my other 5s. Some of the data I'll be reading from the 5 will be used for a form of cascaded PID. After some math, this will be moved to the .sp of some clx pid loops who's update time will be 500 ms.

I wonder if a DHRIO connected to the same DH+ would improve things? I'd still have the issue of uploads interfering.

I'd love to get an ethernet sidecar for the 5 but that 1771 rack is full. Lots to move.

Would a RIO module be a better bet? My RIO is at 230k as opposed to my 57k DH+.

rjd007, can you provide any links to more info on the RIO module?

Also, I notice that my IO config is showing a warning. I've read that if both channels of the DHRIO module are set to DH+ then I have to live with the "IO Not Responding" warning. Well, that's what I've got. The second channel is not used. Would disabling or changing CH2 to to RIO or OFF (if possible) get rid of the little yellow warning signs?

wildswing said:

...
I've been able to set up the comms as suggested, through and existing CLX bridge, so...

NewCLX > Ethernet >Existing Bridge > DH+ > PLC5

Click to expand...

That's what I would have done...just stick it on ethernet and msg through the existing gateway.

wildswing said:

I set up the write and read in the CLX so that the write is triggered by a timer .dn, then the read goes on the write.dn. For now the timer .pre is set to well beyond what the write/read takes just for testing I watched it for about 20 minutes. No errors. I find that a complete write/read takes a little over 1/2 second (64 intg words each way). Lowering the number of words does not seem to make it much faster, maybe a little.

The speed is ok for now, but I did give it a challenge. This bridge is the same we use for programming. It's connected to all of our 8 PLC5s. I intentionally uploaded from both the target PLC5 and another to RSL5. The write/read cycle slowed down a lot during the upload form the target. It peaked a few times around 2 seconds. Not sure if I like that. It only slowed a little when uploading from one of my other 5s. Some of the data I'll be reading from the 5 will be used for a form of cascaded PID. After some math, this will be moved to the .sp of some clx pid loops who's update time will be 500 ms.

I wonder if a DHRIO connected to the same DH+ would improve things? I'd still have the issue of uploads interfering.

Click to expand...

Probably.

How many nodes would that give you in total?

Adding a node will slow the token passing a small amount, but if that node has only one responsibility (handling the high speed MSGs) then the performance could improve. if the new node was a DHRIO in your new system chassis, then why would it be needed at all during the uploads and downloads? Those processes may slow the token passing down, but it would be a different module handling the data for up/downloading. This is one of those deals where trial and error might be the fastest way to find out, because I think the comms timing calculations could get pretty hairy with what you have so far.

wildswing said:

I'd love to get an ethernet sidecar for the 5 but that 1771 rack is full. Lots to move.

Would a RIO module be a better bet? My RIO is at 230k as opposed to my 57k DH+.

Click to expand...

The baud rate makes less of a difference than most people think. It might be faster simply due to fewer nodes and MSGs to deal with. Using RIO would be my last resort, though, because it will not break for ten years, and then confound the heck out of whoever has to figure out how it works.

Thanks OkiePC. Adding a DHRIO module to the millwide DH+ would be the 11th node.

Sorry 'bout the confusion. When I mentioned interference from uploading, I meant from the target PLC. That RSL5 is using the same DH+ port on the 5 as this MSG is. While RSL5 is using up bandwidth reading/writing to the 5, the MSG in my CLX slows down. Doesn't happen very often. Just a test I ran to see what effect it would have.

There is one other possibility. 2 of the 4 channels on our 5s are DH+ (the other 2 are RIO). The one I'm using now is a millwide programming buss. The other DH+ ch is used for HMI comms. 2 PLC5s connected to another 2 redundant bridges (only 4 nodes), talk to a Wonderware Intouch daserver in one of a pair of HMIs. Maybe I'll try going through one of those bridges to see how it behaves.