Drives

[gojuman]

Does anyone access to a pre-written SLC 5/05 code to control (Send/Receive Messages or controls) multiple PowerFlex 40 drives with 22-COMM-E modules? (Did not see any sample code on the website… found some basic examples in the 22-COMM-E user manual).   I Also have one PowerFlex 755 in the mix.   Kinda in pickle… our delivery date of the system was recently pushed up and I probably waited a bit too long to get busy on the programming.

Thanks in advance for any help or suggestions.

[fuzzy_logic · Accepted solution]

Try to start from document attached to Aid 52205.

It contains some instructions and screenshots for a Micrologix 1100, but could also be used with SLC; just the message settings aren't exactly the same, you may find below an example on how to *convert* the first message indicated in the technote:

Anyway you may see other examples of Ethernet/IP messages to a PF in Aid 28652, where you may also find some informations about MSG settings and Multihop.

Hope this helps,

- fuzzy logic

[Ken_Roach]

I have a working example from my test lab that may be of use to you.  To compare the Ethernet Explicit Message (EEM) and the ordinary MSG instruction, I used one of each.   You might want to just use MSG instructions for both reading and writing to the drive.

The Comms Timeout feature of the 22-COMM-E can be tricky to handle.   I found that if the Comms Timeout is zero, when you attempt to write a command to the drive there is a specific error code returned.   When the logic sees this error code on a Write, it sends a nonzero value to the Comms Timeout feature.

This example only handles one PowerFlex 4-series drive.   I'll see if I have an example that handles several at once.

I posted this example on another Forum a few years ago;  I'm not sure if the RA Samplecode site was around then.

[Ken_Roach]

I looked at the multiple-drive example and I wasn't satisfied with it, so you can just expand that single-drive example to run in sequence or in parallel.

It is important to take a step back here and emphasize that controlling AC drives over EtherNet/IP with a MicroLogix or SLC-5/05 controller is a parlor trick;   it takes advantage of the PCCC Object inside the AC drive and by no means turns these controllers into I/O scanners over EtherNet/IP.    That is the exclusive province of the ControlLogix-family controllers.

In addition, I recommend against this method because it leaves the reliability and speed of the drive control in the hands of the individual programmer, not the firmware of the Ethernet module.   I tend to see this mechanism used where somebody just saw "Ethernet" on the data sheet and figured that everything would just be integrated easily like it is in ControlLogix.

I very much prefer to use hardwired I/O for the Start and Stop control of the drives, and to use the Ethernet for noncritical speed control and feedback/monitoring data gathering.

[Greg Smith]

Thanks to all who helped me with this MSG'g debacle.  I originally started the ball roll on Nov. 18 with our local sales support... we received many good tips and assistance from both Rockwell factory tech and local sales support.

Attached is a copy of the SLC 5/05 program used to communicate to 4 separate PowerFlex 40 drives (each with it's own COMM-E module) and 1 PowerFlex 755 drive.

Also, I would never recommend this configuration to anyone.  Control/Compact Logix is definately the way to go for the best straightforward solution. TIA !