Servo DNet satus on E-stop

Steve Kemp

Member
Join Date
Nov 2003
Posts
122
Hi all.

I'm testing a devicenet setup on the bench before installing it in a machine. It's a slc with 1747 scanner and some SMC pneumatics bits and pieces plus an AB 3000i servo. When I kill the line power to the servo, as would be the case in an E-stop situation, the scanner shows a status error as it has detected the power loss. That in itself is no big deal so long as it doesn't throw anything else off balance. Everything else seems OK (continuing to operate), but I wanted to make sure.... Any comments?

Thanks.
 
Would it be possible for the E Stop to to kill motor power but maintain control power? That way the node won't drop off the bus. I've seen quite a few servos where the control power is connected to separate terminals. The E Stop contactor opens only the three-phase power feed.
 
Steve,

Yes, I've used the proprietary connector for the limits, etc. This includes provision for an auxilliary 24VDC supply. I used this facility to prevent the -problem?- that I'm seeing now!
 
Exactly what error shows up on the 1747-SDN scanner ? If it's just Error 72 (later Error 78 if the drive stays off for more than a few seconds) alternating with the Ultra3000i node number, then the rest of the DeviceNet will continue to operate normally. The 1747-SDN will send a request to reconnect every few seconds to the Ultra 3000i, but that doesn't affect I/O performance at all.

If the error on the 1747-SDN is Error 91 or 92, that's an error on the whole network and everything else will be offline and not communicating with the scanner.
 
Are you using a 5VDC power supply with the drive to maintain the logic power to the drive even though the AC to the servo is off?

I do not remember getting a DeviceNet error when killing power to my servos. I had the 5VDC power supply though. Incase you didnt know the 5V gets hooked up to one of the D-Sub connectors (I cant remember which one).

Good luck!
 
Steve (Crotty), Got it in one. I had connected the 24V I/O power and thought that was it... Wrong. It's pins 1 & 2; auxilliary encoder power. I thought that was for an aux. encoder :oops: Although it shows pins 2 & 3 on the diag. elsewhere :confused: Anyway, all done.

beerchug
 
It would probably be nice if details like that were included in the manual. Since the DeviceNet cable includes a 24 VDC supply, one might be forgiven for thinking that if you maintained 24 VDC power on a node, that node would remain on-bus.

[Sarcasm]
How silly not to notice that terminals labeled 'auxiliary encoder power' were the key to maintaining the node's presence on the bus.
[/Sarcasm]

[Rant]
Why can't the team of writers, proofreaders and editors responsible for the manuals for these products include at least one person who has actual hands-on experience with making the product work?
[/Rant]
 
Ultra 3000 servoamplifiers aren't the only devices that don't get all of their logic power from the DeviceNet. They gulp down nearly 2.5 amperes at 5 VDC, so the draw off the DNet network supply would be prohibitive in many network configurations.

And Steve (Kemp), double-check your power connection ! The Auxiliary Encoder Power Out (+5V) is an output circuit on Pin 1 and you shouldn't be trying to feed the main control board through it !

The Auxiliary Logic Power Input (+5V) for the Ultra 3000 drives up to 2 KW with DeviceNet is labeled on page 2-19 of the user manual:

[attachment]

The 3 kW version of the drive shows that pin as "Reserved" so maybe those drives don't support an auxiliary logic supply. If you're using one of the larger drives, then I think a call or e-mail to Technical Support is in order to be sure you don't damage the main control board by backfeeding the auxiliary encoder output.

page_2_19.gif
 
p.s. Many users who want to connect stuff up to the CN1 connector use a breakout board that includes a 24 VDC to 5 VDC converter onboard. On that board, the +24 VDC and DC Common are labeled "X+ and X-".
 
Just curious, is that breakout board very expensive? Ken, would you by any chance have a model number kicking about somewhere for them? What are its advantages?? just easier to wire up? Could it help with trouble shooting at all?

We have a customer with 14 Ultra 3000's on a machine, and I have been getting alot of errors on their drives. For a lot of the errors the solution seems to be tweak the 5V powersupply higher. Whats the point in having "5V" power supplies hooked up to them when you got to set all the power supplies to 6V.

Anyways, any info you got on those breakout boards would be greatly appreciated!

Thanks!
 
Wow, has it really been two years?! BTW, It all worked well, complete with dynamic brake module- stops "on a dime"! You can vault through the light guard and safely grab at the two metre belt-driven slide assembly. Very good. Belated thanks for the guidance. Steve.
 

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