from where in the UMI flex 6c I should give enable to servo motor amplifier/driver.

[vkmehta]

I am using ADS 50/5 maxon amplifier to run the maxon servo motors with Flex 6C. The problem I am facing is that, How to enable the amplifier so that it works only when desired. I have tried by connecting the enable to the inhibit output but it is not working. before connecting to enable Inhibit output is showing 5v but as soon as I connect it , it drops to 1.5V. I am giving encoder feedback to 6C. Motor runs when I directly connect enable to the power supply, but then it runs continuously. Can anybody suggest me about the correct connections.

regards
vkmehta

[Koninika 73]

Hello VKMehta,
Look at the UMI User Guide and on page 25 you will see the table for Inhibit Input Configuration. Most drives require the active low input so that would be the first configuration but do check what type of input your specific driver requires.
Good luck with your application and have a great day!
Regards,
Koninika
Applications Engineer
National Instruments
http://www.ni.com/support

[Buechsenschuetz]

If the output voltage of the inhibit output drops to around 1.5V as soon as you connect it to the enable input of your servo amplifier you should check the specifications for the enable input of the amplifier. It seems that an optocoupler is used, and if you apply 5V without any series resistance to the input led of an optocoupler the input voltage will be clamped between 1.5 and 2V. Also, the optocoupler may get damaged due to excessive current on the input led.

Check the manufacturers specifications for correct input wiring. In most cases a series (current limiting) resistor is needed, somewhere around 470 ohms.

You should also check whether you are applying the correct logic level to the enable input. Some servo amplifiers need a logic 1 (= 5V) on t
he input, some require a logic 0 (= 0V) to shut down the amplifier.

[Buechsenschuetz]

Just an addendum: since the inhibit output of the UMI can sink more current than it sources, in most cases it should be used as a low side driver. I.e., you should connect it to the catode (low side) of the input led of the optocoupler of your servo amplifier. The anode of the led should be connected to +5V with a suitable current limiting resistor. This +5V supply must have the same reference point (ground) as the UMI box, i.e. GND of the power supply and GND of the UMI box must be connected.

[vkmehta007]

Namaskar Koninika
Thank you for your reply, I have gone through that manual and corrected the mistakes. Now I am getting 5V signal from inhibit output when it is desired.

regards
vkmehta

[vkmehta007]

Ya you were right, that GND of UMI and Power supply should be connected. this was one of the mistakes which I was doing. Now I have corrected it and I am getting desired signal. Thanks for your suggestion.