You are not registered yet. Please click here to register!


 
 
plc storereviewsdownloads
This board is for PLC Related Q&A ONLY. Please DON'T use it for advertising, etc.
 
Try our online PLC Simulator- FREE.  Click here now to try it.

---------->>>>>Get FREE PLC Programming Tips

New Here? Please read this important info!!!


Go Back   PLCS.net - Interactive Q & A > PLCS.net - Interactive Q & A > LIVE PLC Questions And Answers

PLC training tools sale

Reply
 
Thread Tools Display Modes
Old September 15th, 2006, 05:41 AM   #1
kenschunk
Member
United States

kenschunk is offline
 
Join Date: May 2006
Location: Saratoga Springs, NY
Posts: 53
Question AB MO2AE & Yaskawa SGM drive

I'm wondering if anyone here has used these two devices together? I've got a system that is in startup testing that is exhibiting some rather odd behaviour. The MO2AE card (1756, in a ControlLogix chassis with a L61 CPU) is connected to two Yaskawa SGM drives. The connection is set for velocity mode, and the servo cards are configured for that. There are encoders (8192 PPR) connected to the drives, and the drives send the position signal to the servo card.

Everything worked pretty much as I expected for the first axis on the card. When I powered up the second axis, however, things went south. The system acts like there is a cross connection between the two servo drives on the velocity signal. If I home one of the drives both drives will move towards the home position. The drive that shouldn't have moved will travel the same distance as the homing drive, and then will slowly (over 30 seconds or so) return to the correct position (with position faults which I disabled while looking for this). If I execute a MAM command on one axis the second axis will follow. It doesn't matter which axis is commanded - the other tries to follow.

Direction seems to matter - both move together towards positive positions (which, with the motor connections, is produced by a negative voltage output). Negative positions, however, are a different matter. If one drive is a -3.0, the second drive can be moved to -3.0 quickly. Moving it to -4.0, however, causes it to get to -3.0 or so quickly, and then slowly drift up towards -4.0 (over 10's of seconds). What is odd there is that the MAM instruction reports that it's in position when in fact it is not. Moving a drive that is at -4.0 to -3.0, with the other at -3.0, results in both drives moving positive 1.0, and then the uncommanded drive slowly returning to the proper position.

The axis aren't linked in software in any way (other than being in the same motion group), and I've checked the wiring a few times. Hooking up to one of the drives with Yaskawa's software shows me that the drive that isn't being commanded sees the velocity voltage signal change when the commanded drive moves.

I've swapped MO2AE's (on the remote chance it was bad), checked the wiring twice, tied the SG on both drives together (which, from the prints, appears that it connects to the OUT- on the MO2AE), disconnected the SG's from each other, and tried one drive at a time. With only one drive powered up it works fine - as soon as I power up the second drive the problems start. I've even tried lifting the OUT+ wire from the servo card - that makes no difference. I'm suspecting some type of isolation problem, since if I lift both the OUT+ and OUT- wires the other drive works fine, and doesn't change if I command the drive with the disconnected wires (which, to me, eliminates the chance that the card or software is causing this).

So, my question after this long winded explanation, is anyone have any idea's here? I doubt it's software, since all that is in the current test program are two MAH and two MAM instructions, and I ensured they all used different variables.
  Reply With Quote
Old September 23rd, 2006, 07:25 PM   #2
kenschunk
Member
United States

kenschunk is offline
 
Join Date: May 2006
Location: Saratoga Springs, NY
Posts: 53
Just in case anyone else is looking to use this hardware I'll answer my own question.

They work just fine together. I checked the wiring twice, but to the electricians list of signals on the multiconductor cable. He wired it like he wrote it - too bad what he wrote didn't match reality. Once I wired the OUT+ to the signal input, and the OUT- to the signal ground (vs. the other way around) it worked fine.

Oh, and it's a SGDF drive - the SGM is the motor.
  Reply With Quote
Reply
Jump to Live PLC Question and Answer Forum

Bookmarks


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Topics
Thread Thread Starter Forum Replies Last Post
Abb Ac Drive rajendrad LIVE PLC Questions And Answers 13 November 5th, 2006 10:18 AM
Device Net with AB 50/4 and ABB Drive 504bloke LIVE PLC Questions And Answers 37 March 30th, 2006 02:58 PM
AB 161 Drive (or, why I don't play the lottery)... Eric Nelson LIVE PLC Questions And Answers 5 April 11th, 2005 08:19 PM
Ab Drive Problem?? vinuvinod LIVE PLC Questions And Answers 3 August 17th, 2004 09:58 AM
AB Drive Tools(V2.06) W/SC 300 Interface Vietnam Bob LIVE PLC Questions And Answers 0 November 20th, 2002 09:19 PM


All times are GMT -5. The time now is 10:55 AM.


.