friedmators

Solved this.  I need to write to N45:0 and N45:1, all 32 bits.  Does not work if I only try to write the first 16 bits or an individual bit.

Hello,   I am trying to interface with some Powerflex 753 VFDs using a PCCC datalink.  I am able to successfully write to N42:3 to set my timeout settings.  I can read from N45:0 through N45:3 to get the status and drive hertz feedback.  However, when I try to write to N45:0 I receive "Extended STS Error: Address does not point to something usable.  I have the drive setup in CCW and am able to start it fine so I know it is functional.  Any thoughts?   Thanks for your time

Well we are about to find out. I work for Emerson so maybe I am biased. :)

Thanks for the reply.

Thanks Ken, I agree this is a non-standard setup. My only guess is the client doesn't want to spend the money. Rockwell also recommended against doing it this way. The drives are Powerflex 750s and we are using Ovation for control. I can use PCCC or Native for protocol types.

I have a customer coming in with some Rockwell drives to see if we can control them directly using explicit messaging instead of going through a PLC. I have my end setup but was wondering if there exists simulation software (free) that can mimic some EIP tags and allow my controller to connect and try to read data. I also have a full version of RSLogix so maybe it has some sort of capability like that as well. Any thoughts would be appreciated. Thanks

The mapping is indeed missing. Thanks for all your help.

Quick update: Using the Wonderware AB CIP Driver, I was able to see data from the PLC using the tag name itself. However, requesting N10:0 resulted in a similar error the Ovation DCS was reporting. Seems to be a mapping issue. Ovation allows Slot selection. Everywhere else on site its Slot 0, here its slot 7. 44818 for slot 0, 1792 for Slot 7. Non-redundant. I am thinking we are going down the right path. I have another PLC using the same exact ethernet card and revision number and N registers and its working in Ovation. I was going to confirm wonderware can speak to it using N registers which would pretty much isolate the issue down to the mapping. I did a cursory glance at the configurations of the two PLC's and couldn't find any differences other than the location of the ethernet cards/CPU in the I/O tree though.

Thanks for the reply. We are talking to Ovation here. Not sure exactly what you are asking since I am an Ovation guy but the controller is a 1756-L61 Revision 16.7 We have 1756-L63 Rev 16.56 working here amongst others. Is there a way to debug from the Rockwell side to see why it doesnt like my requests?

Hi, Have a DCS system trying to communicate with some recently retrofitted Control Logix processors. They used to be serial and were converted to ethernet. When making data requests I get a 'read reply error: address doesn't point to something usable'. Removed all points except one from my requests to narrow it down. I am requesting N10:0 which looks to be correctly mapped inside RSLogix. We have other similar processors working on site so I know this is not a driver issue per say. The only thing I see odd is when I connect in Logix, the new ethernet card is not listed. Using Linx I was able to configure the card with an IP and gateway and I am connecting up through that card so it seems to be working. Any thoughts would be appreciated.

Thanks for the reply. I actually figured it out. They had some simulation routines that were running bypassing all the I/O. Soon as i disabled that bit and went to run mode everything started working.

Trying to figure out why when I lift the hard IO signals, the ZSO/ZSC signals don't change. Picture below. I am an Ovation guy so this is all new to me. I am sure it is something beyond simple. Thanks for any response.