UMI "V" LED off when power is applied

[Martin.D]

 Hello all,

Has anyone seen the "V" LED go off after a successful power-up of a UMI-7744? We power our encoders from the UMI so we lose feedback when this failure occurs. Both "Viso" and "V" are powered from the same supply at 24v. The "V" LED goes off ("Viso" stays on) and power is not supplied to the individual axis connections as it should be, when I measure the voltage supplied to the UMI (Viso & V) it's at 24v as expected. I'm guessing that the UMI has an over-current trip inside and switches power off when too much current is demanded, then does not switch on again until a power cycle. Or maybe we have a faulty UMI? Has anyone seen anything like this before?

-Martin

[JamesC]

Hi Martin

If you read the UMI-7774 manual, which is the device I assume you were talking about, in chapter 2 Installation the following is listed:

Required Materials

The following items are necessary for installing and getting started with
the UMI-7774/7772:

‘ UMI-7774 or UMI-7772

‘ 24 ±10%; VDC power supply (10 W minimum)

‘ 5 to 30 V isolated power supply (10 to 60 W minimum, depending
on I/O requirements)

From what you have written in your message I would suggest you get another power supply between 5-30V and attach that to Viso.

Hope this help
Kindest Regards

JamesC

[Bruno_Cesar]

Hello Mr. Martin,

I would like to ask you if your problem was soved. If yes, please let me know because I have exactly the same problem.

Regards,

Bruno.

[Martin.D]

Hi,

Sorry for the massive delay in getting back to you. In my case the problem was a wiring short - when a motion stage neared one limit of travel the limit switch would short the psu. This resulted in loss of encoder signals because they were powered from the same supply. It's amazing how fast the motion stages move when they have lost feedback! This was a lesson in why to use the inhibit signals in a fail safe manner.

Regards / Martin