P7000 Current reduction is disabled.

[RangerOne]

Hello!

I have a third-party stepper motor. I have connected it to P70530 Device. And I have NI PXI-7340 and UMI-7774 in Stepper motor control system:

NI PXI-7340 <---> UMI-7774  <---> P70530 ----> third-party stepper motor

All of this devices are working, stepper motor is driving, but I have a problem with Current reduction - I need to turn off step motor when it is not driving.

When I connect only P70530 ----> third-party stepper motor (without PXI and UMI),  and make connection with PC (via RS-232 Serial connector), I have Current reduction is working - there are no current in step motor wires. But when I connect all system:

NI PXI-7340 <---> UMI-7774  <---> P70530 ----> third-party stepper motor

Current reduction is disabled - motor stay without control pulses but there are current in step motor wires, and shaft is holding.

Where can be a problem?

[Jochen]

In general current reduction is meant to reduce the current by a certain amount, when the motor is stopped. I don't understand exactly, why current reduction is not working for you, but if you want to turn off the current completely, you could stop the motor with the kill option. This asserts the Inhibit output signal of the 7340 to disable the drive. This will turn off the motor current completely.

If you want me to help you to investigate, why current reduction is not working for you, please post the settings of the P7000 tools.

Thanks,

Jochen

[RangerOne]

Jochen Thank You for answer,

Here is some things:

1. I have try to use Current reduction as full current off, because with help P7000 Software it is possible to decrease current for 1% in Current reduction mode.

2. When I try to kill axis (in Measurement & Automation Explore) I have got Disabled LED is light on UMI-7774, and I have got blinking green LED on Status  of P70530. And Motor have current in wires, shaft is holding.

3. I do not know how I can give You P7000 setting? (I will try to save setting and Attach file, is it - ok?)

The another thing - I do not know - is it important or not....

I make all this things for training and understanding how all system is working... So I have use third-party stepper motor, but I have set in P7000 Software CTP10xxx16 motor - it is similar for my motor. (Why I do not make my own motor file with help - motor file editor? So it is because I have some difficulties with changing of motor database - I have not administrative privilegies on my computer)

And the last question: For conection between UMI-7774 and P70530 I am using HDB26M-DB15M NI-cabel (198141A-2R5).

And the P70530 has the Enable input - it "removes current from the motor windings so the axis can be externally moved". And UMI-7774 has the Enable output. So how it working? When I press Kill axis is pulse-generation  on Enable output of UMI-7774? And How Enable output of UMI-7774 connected with Enable Input of P70530? (I have try to find the pinout - but http://forums.ni.com/ni/board/message?board.id=240&thread.id=6046  - all that I have got.)

Thank You.
 

Message Edited by RangerOne on 09-24-2009 11:31 AM

Message Edited by RangerOne on 09-24-2009 11:31 AM

[The_Chancenator]

Hi RangerOne,

First, here is the pdf for the P70530 Drive. 

Where are you setting your inhibit output settings?  Here is a helpful article that talks about two options--one in MAX, and the other in LabVIEW. 

Also, please see these two articles: 

http://digital.ni.com/public.nsf/allkb/619A2A562CD3188386257156004F7B1D?OpenDocument

http://digital.ni.com/public.nsf/allkb/0B2217C7F1293E17862569E70001267E?OpenDocument

They both go over how to set those inhibit output settings. 

After you have gone through these, and if you still aren't getting that inhibit output to "free" the motor, then look at the settings on your UMI board- is it set to a high polarity or low polarity?  With a DMM, are you able to detect any difference between when it is enabled and when it is not?  Use the DMM to just manually measure the signal that is going to the motor. 

Cheers!

[RangerOne]

Hi Marti C,
Thank You for Answer,

About inhibit output settings. Thank You for links.
In the first step - Let speak about MAX.

1. I am setting inhibit output as it said in: (http://www.ni.com/pdf/manuals/373359b.pdf)
National Instruments Universal Motion Interface (UMI)-7774/7772 User Manual pg. 3-12:

"You must configure the National Instruments motion controller Inhibit Out signals
as active-low for proper operation of the inhibit logic on the UMI-7774/7772."
So here is screenshoot of my Inhibit Out signals in atachment.

2. And the Switch settins of UMI board I have made as in:
(http://www.ni.com/pdf/manuals/372324c.pdf)
Getting Started with the P7000 Series Stepper Drives pg. 22:
Fault - Active low, Enable - Active high, (And LIMIT LED - Active high).

3. And I have Active Open - Enable Polarity setting in P7000 Software.

With these settings, there are not any lighting LEDs on UMI and motor is driving (starting, stoping, accelerating, decelerating...), but when I am pressing Kill axis, Disable LED on UMI board become light, but (and it is defferent with my last post, why I have got "Amplifier is disabled"  - blinking green LED - yesterday I can't understand) LED on P7000 is not blinking - it is mean that Amplifier is Enable.

With help DMM I have measured voltage on wire and it is not changes with working axis or killed axis.

After it, I have check P70530. I have connect J4-6 (Enable-) and J4-25 (5 V Return I/O Power Source), and switcher connect: J4-5 (Enable+) and J4-19 (+5V I/O Power Source). When switcher On - I have a "Amplifier is disabled" - it mean - P70530 is working.

After I start interesting - what kind of signal I have on UMI Enable Output. (The best way is to investigate signals on HDB26M-DB15M NI-cabel But because it is unassemble, I decide to  investigate signals on free Control connector of UMI-7774). And I have got almost square pulses  - see atachment. (It is between Control conector Pin 15 - Iso Common and - Pin 6 - Enable) . And there is no depend  axis killed or not... Is it normal or maybe I have made something wrong (I have connected V with Viso and C with Ciso - I have not separate power)? I have thought that it must be constant level, and when press Kill axis it must change.

So I think, I need to check HDB26M-DB15M NI-cabel, and I will try to do it on Monday.

[The_Chancenator]

Hi Ranger,

Taking a step back, we can confirm a few things with your configurations.  In terms of your second post, where you mention the status of the LED's, this confirms that everything is wired correctly with the NI products.  According the drive manual, the blinking green indicates that the drive is online but not enabled, which signifies that you have succesfully killed the motor axis.  (Also indicated by the LED on the UMI board). I'd like for you to double check the dip switches on the drive itself. In order to use that serial cable, the rotary dial should be set to  "use GUI" (which is 0), and switch 2-1 should be set to "off" (which is up in this case). 

Try this, and please let me know how this goes. 

Cheers, 

[RangerOne]

Hi Marti C,

Thank You for answer,

About dip switches on the drive P70530 - S1 Set in 0, and all other 12 swithcers set in OFF (High). These settings of P70530 I am using during all time of my work with Motion control system. (In fact, once, I have made experiment with another settings, but P7000 Software have informed me about that I have not use Custom settings and it was impossible to make some change in P7000 Software. After, I have set all switchers in 0 (S1=0, and all other 12 swithcers set in OFF )).

[RangerOne · Accepted solution]

Hi All!

Today I have solved the problem!

I have start from the begining - power supply. I have used Acopian 24V unregulated power sourse for power UMI and P70530. And it was realy "unregulated" - it gives 27,7V on output - it is not bad for Power Amplifier, but for UMI input voltage it is possible use only 24V+-10% (26,4V - max). After I start use another power sourse with exactly 24V output - All start work right. Axises are killing, shaft is free.

Thank's All support teem for help.

[Tacchi]

Hello.

I'll use P70530 to drive my motor. The drive output is 5Amps, but what my motor needs is 1.5Amps.

My question is if I can control the output current or it is constant 5Amps?

I'm not speaking about current reduction in a standby mode, but operating mode.

As i understood from the manual i can use P7000 "Operating Current" but i want to be sure 🙂

Another question is about P7000.

If I use it, so the driver must be connected to the computer constantly, or once I made the setup I can disconnect it?

Best Regards,

   Mihael 

[Jochen]

Hi Mihael,

first of all, please note, that it is much better to start a new discussion thread for new topics instead of reusing an older thread.

To answer your questions:

1. Yes, you can limit the current of the P7000 by setting the operating current value. 
2. Are you talking about the serial connection? In fact you can disconnect it after the setup, but as the P7000 is meant to be used with an external controller like a PCI-7330, or a cRIO-9512, you need to keep the connections to the external controller.

Regards,

Jochen