AB Powerflex 400 Parameters

andrewbe

Member
Join Date
Aug 2007
Location
Appleton, WI
Posts
35
Alright - first off, I am BRAND new to the whole concept of PLC's. I am fresh out of college and in a software engineering job, and I have been given the task of figuring out why a custom application that we have is having issues programming a Powerflex 400. I have done a bunch of researching on the ActiveX control that we use, which led me to PLC's and all that jazz. I won't go into too much detail of the exact problem I am having (unless I need to) but will say that I have contacted tech support at both the company that made the control (Automated Solutions) and Rockwell. The AS guy told me that he needed a copy of the memory map for the drive. Not sure what that was, I contacted Rockwell, who referred me to the bit layout of the Logic Command word and Logic status word. This certainly didn't seem like at all what I needed (although I forwarded it to the AS guy just in case)

Basically - what is this memory map and how the heck can I access it? Try and be patient with a COMPLETE newcomer to his area, and I will greatly appreciate any and all help and pointers. Thanks in advance :)
 
A little more info that might trigger something in someones brain. The control that I use has the ability to read using PLC5 and SLC500. PLC5, for some reason, doesn't work (the support guy says they use the Word Range Read command) when I attempt to read anything. When I attempt to read N150:321 (the drive type parameter of the PF400), I get an error (I read somewhere that SLC500 cannot support anything above 255) If this is the case, what am I do?

Again, I hope my ramblings make sense, my head has been spinning all day with all the articles and such I have been reading and talking to two different support guys from two different companies who don't seem to know whats up.
 
Look in appendix F of the manual, 22C-UM001B-EN-P.PDF. Powerflex 4 series drives support Modbus RTU communications for free. I don't know if this is what you are looking for, but it's a place to start.
 
I had looked in here (since the Rockwell support person led me here) but I am not sure at all how to interpret this data (like I said, really new, heh)
 
You will have to explain a bit more of what you have installed.
A)Is there a SLC500 or PLC5 connected to the PF400 and you are attempting to access drive data from the PF70 via the data tables in the PLC using an Active-X control.
OR what I think you are trying to do
B) Directly trying to control the drive with Active-X commands from the AS system.

If you are trying to use B then the N??:?? has nothing to do with it. The N??:?? live in a Rockwell PLC of which you dont have. I am guessing you are using one of the freely available Active-X thingos that were meant to access a PLC. They will not access a PF400 and if AS are trying to tell you they will then they are a bit clueless.

If it is option A then the PLC programming will determine where the drive data is stored and in which order. You are correct, in a SLC there is a limit of 256 words in an N file.

Please give us as much detail as you can otherwise everyone is guessing.

Regards Alan
 
andrewbe,

are you sure the drive is a PF400?
I have seen PF4,PF40,PF70,PF700, but never a PF400. Maybe you have the latest greatest version that I am not aware of. Can you provide a drawing of the communication wiring? Is the RS232 cable going from a PC's 9 pin serial port directly to the drives Comm-22 jack, or what? The field of work that you have entered can be thrown all out of whack over the tiny details involved. I'm sure that you will become very aware of this in the near future. Machine control programming & wiring is not plug & play nor drag & drop. Each & every detail must be brought out into the light, examined, thought over, tossed around & decisions made about them. Have you looked at Rockwells application named "Drive Excutive"? Are trying to develope a similar application? Drive Executive Lite is free & can read & write to most if not all PowerFlex drives.
BD
 
andrewbe,
a quick trip to the AB web site & I answered my own question. There is a PF400 drive, I didn't know that, must be a new model. looks like someone wants you to learn to swim by throwing you in the deep end of the pool. I didn' see a 22-com-232 adapter available for this model though.
options:
22-comm-b ,BACnet
22-WIM, Bluetooth
22-COMM-C ,ControlNEt
22-COMM-D , DeviceNet
22-COMM-E , Ethernet
22-XCOMM-DC-BASE , External COMM Kit
22-COM-L , LONWorks
22-COMM-P , Profibus
22-SCM-232 , Serial Converter
1203-USB , Universal Serial Bus


BD
 
I think I can help, Andrew.

You're using an Automated Solutions ActiveX that is meant to read and write PLC-5 and SLC-500 controller data tables using a protocol called DF1 Full Duplex. The Integer data type is a very common data table in PLC/SLC, so that's where these references to "N" data types come from. (N=Integer, from way back)

The PowerFlex 400 drive doesn't natively "speak" DF1 Full Duplex. It's native protocol is what Rockwell calls "Drive Serial Interface" (DSI), the core of which is another common protocol called Modbus RTU.

The 22-SCM-232 converter not only converts from RS-232 signalling to RS-485 signalling, it also converts from DF1 Full Duplex protocol to DSI protocol.

If it were my choice to use a software interface to the PowerFlex 4/40/400 drives and I didn't have to interface an A-B controller as well, I'd cut out the middleman and use a physical RS232/RS485 converter and a Modbus RTU protocol ActiveX control.

[more shortly]
 
Because the PowerFlex 400 drive is newer than its little cousins, we're going to do a little bit of extrapolating.

In the 22-SCM-232 User Manual (22COMM-UM002) is the following general principle, on page 4-4:

PowerFlex 4 and 40 parameters are addressed using Integer File N150:x, where “x” equals the actual parameter number in the drive. For example:
N150:39 = Parameter 39 - [Accel Time 1]

From the PowerFlex 400 User Manual (22c-UM001), we find that the Drive Type value is in fact Parameter 321.

So it makes sense that if we try to read N150:321 that we'll get the Drive Type value.

Post the exact error code that the Automated Solutions software gives you.

Try reading a different value, like Parameter 5, the DC Bus Voltage. Or try reading one of the values in the drive's Status data table, like Drive Status N183:198.

As you have seen, there are multiple DF1 function codes that can be used to access the same data table addresses. Maybe you're just unlucky that the Automated Solutions program uses the PLC-5 Word Range Read function and the 22-SCM-232 doesn't support it. I have not dug deep enough into the 22-SCM-232 documentation or analysis to tell you precisely which DF1 functions it does support.
 
Ken Roach said:
...I'd cut out the middleman and use a physical RS232/RS485 converter and a Modbus RTU protocol ActiveX control.

This is actually something the AS Support person mentioned, but we have other drives (not just Powerflex drives) that use this custom software (as well as different serial connection techniques that I am unsure of) and this seems to be an option that works well for now (hopefully this new drive doesn't throw that all out of whack)

I can read pretty much any parameter under 256 at N150 with no problem. When I start going over 256, I don't actually get an error - but it just doesn't return the correct values. They seem to be random values (not even like the values are being offset by a few numbers or anything, just all the wrong values) - and when I read N183:198, it returned 13.

The way we even knew the issue was even coming up was the software we developed was throwing an 'Illegal Command or format' error, an error I have seen appear when you try to access an address or location that doesn't exist. I was troubleshooting that and noticed that it wasn't getting correct values for parameters over 256. After some research and just random tinkering, I found that the drive type value can be retrieved at N151:327 - which makes NO sense to me. I don't want to just change the program to look there, since I don't know why it would be there (if it were at 321 like it should be, I might be more willing to change the program, but why would it be at 327?)

Thanks for all the replies thus far.
 
bikerdude said:
Have you looked at Rockwells application named "Drive Excutive"? Are trying to develope a similar application? Drive Executive Lite is free & can read & write to most if not all PowerFlex drives.
BD

Also - there is a program called Drive Explorer Lite on the dev machine that I have used to examine the parameters of the drive (using the same serial connection) and they are all returned properly - not sure if this means ANYTHING, but just thought I'd mention it.
 
So I think I might have figured something out with this finally...

According to the SLC500 Addressing Reference Manual that I found on Rockwell's site, a SLC500 really can't have a file with more than 256 elements. From the manual:

The recommended default file for integer elements is file 7 of the data table. This file accommodates up to 256 integer elements. If your application requires more than 256 integer elements, specify one or more files (10 – 255) in the user-defined area of the data table in addition to file 7.

So I thought, well, since everything is currently on N150 and there are about 360 parameters, maybe they went over to N151 (which, well, they would have to) So I tried parameters N150:250 - N150:255 and it seemed to be getting everything correctly. After 255, it wasn't getting the correct stuff. So I went to N151:1 - around N151:10 and it was getting the right stuff - but it was off by about 6. After a little more testing, I realized that it was actually starting from parameter 251, not 256. So if I wanted parameter 321 (drive type), I take 321 - 250 = 71 Look at N151:71 and voila - there it is!

I think if I update my software to look at this new location for parameters over 250, I should be all set.

Mucho thanks to everyone who replied - it helped point me in the right direction when searching for things. I will certainly come back here if I have more issues with this :)
 
Excellent persistence on your part, Andrew.

As a Rockwell employee with some experience with the 22-SCM-232 and the PowerFlex 4-series, I'd tend to point to the Automated Solutions driver as the source of this "move to the next Integer file after element 251" behavior.

Since the 22-SCM-232/PowerFlex 400 isn't really an SLC-500 controller, it's not actually limited to the 256 element limit on data file sizes. The DF1 protocol command that is commonly used to read SLC-500 Integer files is the "Protected Typed Logical Read with Three Address Fields" (see the DF1 reference manual, page 7-17). Usually the Element Number is a 1-byte value, meaning it can be 0-255. But if you put 0xFF into that field, the Element Number field extends to three bytes and can have a 16-bit value.

Since the 22-SCM-232 user manual doesn't address what happens if you request data from the data file "N151", I'm not sure exactly what's going on. This strange offset could be the 22-SCM-232's doing, but it wouldn't make a whole lot of sense.

Again, great persistence. If I get some time and hardware I might look into this just for academic purposes.
 

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