CompactLogix 5000 series I/O light flashing

Man, if you're auditioning for a job offer with your first post on PLCTalk, you're doing a good job !

I used to have all this stuff at my fingertips but now I have to go back and check my assumptions.

I think the critical parameters for your application are stored in the non-volatile flash memory inside the 20-COMM-ER itself, but I'm not 100% sure. That would be consistent with "we set it up at the factory" meaning "we set the IP address but forgot to set the Enable Master-Slave DataLinks".
 
Because I do most of my AC drive configuration within the applets that are launched inside Studio 5000, I don't have much experience navigating CCW software.

Navigate through CCW to look for the parameters that are specific to the 20-COMM-ER module. Parameters 36 and 37 in the 20-COMM-ER itself enable the DataLinks to be part of the Master-Slave I/O connection. You may also be able to get to them from the HIM module if you select the connected device to be the 20-COMM-ER instead of the PowerFlex 70.

The "pointer" parameters 300-317 that define the DataLinks are saved in the PowerFlex 70's nonvolatile memory. But the critical parameters that enable those DatLinks as part of the I/O connection are saved in the 20-COMM-ER's nonvolatile memory.

While these show correctly in Studio 5000, in your case, "automatic device reconfiguration" is disabled, so when the 20-COMM-ER got replaced, the ControlLogix did not attempt to load its new parameters from the set that is stored in the ControlLogix.

Set Parameters 36 and 37 to an internal value of "7" (or click the checkboxes for DataLinks A and B on both Input and Output if that's how they are presented), then cycle power to the drive.

Edit: I see in a previous screenshot that you already got to those in CCW. Parameters 36 and 37 are set to "3", and should be set to "7".

Param_36_37.png
 
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Interesting!!

I think you have cracked it Ken, because there is one piece of information I didn't give that I am now thinking may be relevant based on what you are telling me and my rudimentary understanding of what all this stuff means

When I was initially troubleshooting this networking issue, one of the first things they had me do was check to see if ethernet was plugged into Powerflex 70 20-COMM-ER. I removed the LCD HIM and found that it was. However, the ethernet had been plugged into port 2 (I believe this would correspond to "B" in parameters). They said "it's supposed to be plugged into 1 so try that" which obviously didn't change anything because my 20-COMM-ER ribbon cable had given up the ghost

It seems to me that my programming for 20-COMM-ER parameters #37 and 38 being set to 3 means that Datalink B is not enabled, despite my drive having previously been communicating with the PLC over port 2 from the factory. I surmise that if the PLC was connected to this drive via port 2 when it had last seen it on the network (faulted), maybe it's still waiting to hear back via port 2, which the new drive is not configured to do. Or maybe I'm way off base again! Haha

Here is some relevant information I dug up before you had posted your most recent message. Some of it was posted before as you noted, and some of it I have not posted. I think it might be helpful to have it organized in one place now that our focus is narrowed.

AB literature on 20-COMM-ER M-S settings:
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AB literature on 20-COMM-ER status:
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Parameters I now understand are relevant from 20-COMM-ER and PowerFlex 70:
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Reset procedure for 20-COMM-ER:
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I take it I just need to connect with CCW, change parameters 37 & 38 in 20-COMM-ER from "3" to "7" and then cycle power to the drive? We aren't thinking we need to mess with Powerflex 70 parameters 300-317 at this point, right?

Must I only cycle power to the drive or can I cycle power for my entire machine?

Should I follow the reset procedure for 20-COMM-ER or would cycling power to drive / machine achieve same result?

I tried looking for a "reset" parameter in my Powerflex 70 in CCW and didn't see one like there is for my 20-COMM-ER module. Let me know if there is a "better" way to cycle power to my Powerflex than just cycling power for entire machine

Thank you for all your help on this!
 
I actually like the "wrong port -> wrong programming for field replacement" hypothesis if it holds up in theory, because you can kind of imagine how it happened

Facing the drive, Port 2 is on the left and Port 1 is on the right. You can imagine the guy at the factory thinking the left port was 1, testing machine and it won't run, then plugging in to figure out why, and since fixing it would be as easy as changing a couple 3s to 7s, he didn't feel like physically changing the connection since he was already connected to the module

Could be it was so simple he neglected to send the update to programmer for his records, which is how we ended up in this "field replacement doesn't work with factory programming" headache

I don't know enough to say for sure and maybe I'm getting too imaginative here, but it scans to me as a pretty coherent explanation of how we got here
 
The port numbering conjecture is a little off base and we shouldn't get distracted by it. The 20-COMM-ER is a "Ring" adapter that lets you daisy-chain devices or connect them in a special Rockwell/Cisco "Device Level Ring" arrangement that can tolerate breakage of one of the cable segments.

In your system, either Ethernet port on the 20-COMM-ER could have been connected to the Ethernet switch. They're logically identical for these purposes.

As long as the ribbon cable for the 20-COMM-ER went back into the same receptacle as previously, then it's using the same "DPI Port Number".

The problem I see now is that the *.ACD file has a different setup than what you're seeing in CCW for the DataLinks and the Master/Slave connection.

I'm going to take a closer look at the program to see which features are actually used.
 
The port numbering conjecture is a little off base and we shouldn't get distracted by it. The 20-COMM-ER is a "Ring" adapter that lets you daisy-chain devices or connect them in a special Rockwell/Cisco "Device Level Ring" arrangement that can tolerate breakage of one of the cable segments.

In your system, either Ethernet port on the 20-COMM-ER could have been connected to the Ethernet switch. They're logically identical for these purposes.

Noted. Thanks for the info. And sorry -- I'll try to rein in my conjectures, I'm sure they don't help

As long as the ribbon cable for the 20-COMM-ER went back into the same receptacle as previously, then it's using the same "DPI Port Number".

Could the drive itself having been replaced along with the COMM module (per vendor recommendation) change the "DPI port number" in reality vs programming? Or is that just my "port 5" I see my 20-COMM-ER through in both CCW looking at programming and also while networked with the device live?

The problem I see now is that the *.ACD file has a different setup than what you're seeing in CCW for the DataLinks and the Master/Slave connection.

I'm going to take a closer look at the program to see which features are actually used.

Thanks Ken, I truly appreciate it
 
The parameters you show in CCW are consistent with a PowerFlex 70 set up for only DataLink A, both In and Out.

DataLink In A1 = 436 means that the PLC sends the Positive Torque Limit to the VFD.

DataLink Out A1 = 243 means that the VFD sends the Fault Queue Position 1 Code value to the PLC.

That's consistent with Parameters 25, 37, 38 all = 3.

But it's not consistent with Parameter 26 (DPI I/O ACTUAL) = 1. That should be a 3 also.

And it's not consistent with the values that are shown in the Studio 5000 *.ACD file that you were able to provide.

I *think* that you just need to power cycle the PowerFlex 70 in order to let the drive, and the 20-COMM-ER, apply any changes. You don't need to do any "factory reset" or "reset to defaults".

It's my recollection that the PowerFlex 70 supplies the main control board and periperals with 12V derived from the DC bus, not with a supplementary 24V power supply that you can keep powered externally.
 
Addendum: Any time you change the DataLink programming and the M-S I/O Enable bits, you need to fully power-cycle the drive in order for those change to take effect.

You can also do a "Reset Device" from the HIM keypad or another parameter access method, but removing 480V main power, taking a deep breath, checking your LOTO and tightening your shoelaces is a more thorough method.

Also: I'm willing to bet that he *.ACD file does not match the actual program loaded into the CompactLogix. The tag associated with DataLink Out B1 (Output Current) is not used anywhere in the program, while the DataLink In A1 and Out A1 both are.
 
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Cool

I take it that I need to change Parameter #26 (DPI I/O ACTUAL) from 1 to 3, cycle power, and then we should be in business / be able to start looking elsewhere if the problem still persists?

Sounds like changing my Parameters #37 & #38 for M-S input/output from 3 to 7 couldn't hurt anything either, but it also sounds like you're saying that *should* work based on what you're seeing in the *.ACD

If so, great -- that's something I can do with my software limitations!
 
DPI I/O Actual is a Read Only parameter showing what the 20-COMM-ER is actually doing to move data between the PLC and the VFD.

Usually when you Enable a Data-Link by setting the linked parameters and checking those A,B,C,D boxes, the DPI I/O Configured value (parameter 25) reflects the settings immediately, and the DPI I/O Actual value (parameter 26) doesn't match until after the VFD and network module have gone through a power cycle.

If we get Parameter 25 = Parameter 26 = 3 and the I/O connection is established and runs correctly, then the problem is likely solved.

If not, then we have to guess and test to see if the *.ACD file is correct, or if the other records about the size and specifics of the PowerFlex I/O connection are correct.
 
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Excellent

Thanks for the clarification. I've cycled power on this machine so many times, it's wild I may have just needed to mess with parameters first to get it to actually reset that Parameter #26

And additional diagnostic step I never even considered taking because I was so credulous when the vendor tech support told me that the programming in my Powerflex 70 and my 20-COMM-ER matched how they left the factory is I never tried *just replacing the dang ribbon cable that came with the new 20-COMM-ER*. Or if I did, I definitely don't remember doing it at this point

I'm thinking when I'm on site tomorrow I will try changing my parameters and resetting the 20-COMM-ER / cycling power to see if my DPI I/O Actual reflects the change. If that doesn't achieve the desired result, I will try swapping back in my original Powerflex 70 and 20-COMM-ER with one of the new ribbon cables I have from the bare pre-programmed 20-COMM-ER they shipped me originally, and seeing if they still run right after having caught fire, or at least if I can pull the programming from them and do a comparison in CCW to see if there's anything different in how they're setup vs the programming I got from factory

Something else I didn't notice on the 20-COMM-ER that I just came across in literature is a "web enable switch". Could be another red herring but it's something worth glancing at when I'm on site. I do recall that the switches on the face of all three of the 20-COMM-ERs I've had on this job are set to 999, but I never noticed that rocker switch

Thank you for all of your help and guidance on this. I will be sure to report back with my findings
 
The HTTP web server on the 20-COMM-ER does require you to flip that DIP switch to enable it. As I generally have Studio 5000 available, I seldom use that feature.

I don't think it's going to show you anything you can't see from CCW.

When you get in tomorrow, open up RSLinx Classic software and see if it has activated as Professional or Gateway (sometimes it will do that for a grace period) or if it says it's the "Lite" version. If you have RSLinx Classic that has a license to run as an OPC Server, you can run the OPC Test Client and get a list of the tags that actually exist inside the controller (and read/write them).

What I'm thinking of is to look at the actual tags inside the controller and see if VFD01:I.xxxx contains the .OutputCurrent sub-tag or not. That will tell us if the actual PLC program was set up for 2 DataLinks or just 1.

An OPC tag browser will discover the online tags (at least, the RSLinx OPC Server will). There are surely a handful of other mechanisms, like a program in Python using the PyLogix library, especially since we already know the name of the base tag and the possible variations of the sub-tags.

But most folks are going to use the Studio 5000 Logix Designer software.
 
Update: I finally got that sucker running, thank you!

I get to the job site, energize machine, reset/rearm, get my alarm. Same story, different day

I connect to the PowerFlex 70 and 20-COMM-ER through my ethernet switch. Check my PowerFlex 70 and all I've got is the Drive Power-up marker in my fault queue

I look at my 20-COMM-ER and, wouldn't you know it, my #37 = #38 = #25 = #26 = 3

But my I/O status light is flashing on my PLC! What the heck!

I reset my 20-COMM-ER with parameter #22 = 1 again, reset/rearm on machine, no change -- I/O light still flashing, same alarm, etc.

I say screw it and set #37 = #38 = #25 = 7 because I figure "why not, can't hurt, drive itself is only looking for info on A anyway", reset 20-COMM-ER with parameter #22 = 1, reset/rearm on machine, suddenly I/O light is solid green, #26 = 7, and we are back in business folks

Weird stuff honestly

Glad it's fixed but I'm disappointed I wasn't able to get a hold of my IT dept in time to setup TeamViewer so Ken could see in the live PLC programming, but I am relieved that nightmare is over and that thing is commissioned, and now I just have to train the operators on Thursday, maybe make some tweaks in the settings, and babysit it for five hours. Fingers crossed!
 

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