Axis Disabled LED on UMI not Lit when disabling the Axis in MAX

[M0Reng]

Hello,

I'm using MAX to disabling Axis, Axis2, Axis3 of PCI-7344 and UMI7774,

I click save and "initilize" in MAX, i get message "OK".

The DISABLED LED of the Axis1 - Axis4 on the e UMI is not Lit,

i also notice that in MAX under Motion IO setting, the "inhibit input setting" is grayed.

i found a post of someone with same problem, he said that he 'enabled the inhibit input in MAX' and this solved the problem.

but its grayed un my MAX...

This is his post: UMI-7774 / PCI 7340 Disable Indicator Error

http://forums.ni.com/ni/board/message?board.id=240&message.id=5760&query.id=13536#M5760

But, there is also a knowledge base:  "Inhibit Input Setting in MAX is Grayed Out"

http://digital.ni.com/public.nsf/allkb/01CE29B6175371118625714C0058C2B1

in this article, its ok that it is grayed cause its only used on pci7390...

But he has same hardware as i have... So, what is going here? how can i solve this?

When i'm looking in MAX on "1D interactive" i found that when i change the state of the Limits, its shown in max

"limit switch is active" "home switch is active"...  

The control connector of Axis 1 (the axis i want to work with) is working fine i think..

for example: i test the voltage on pin 3 :  5V as should be.

the UMI connected to V and C 24VDC power supply, and  the Viso,Ciso connected to different power supply.

(V and Viso LED of the UMI is On , ALL other LED is Off.....)

Any help is appriciated, i want to start from begining to troubleshoot what is wrong,

i think that before any wiring is made to the Axis control and feedback connector, the Axis that is disabled in MAX should have their DISABLED Led on the UMI on.

The pci-7344 connected to the UMI-7774 with SHC68-C68-S cable.

Thanks

Moti

[M0Reng]

update:

finally i can run "1d interactive" in MAX, but only after replacing the cables from Axis1 to Axis4.

the wiring is ok, i see the encoder counts in MAX, even when i rotate the shaft manually.

i have some problems yet:

The encoder is 8192 counts/revolution, i set in MAX:  steps/rev = 2048 and counts/rev=8192

but still when i run it in speed of more that 1000rpm, the servo is not responding well, but also there is no errors

and second problem, the "Enable" on the the Axis control connector is always ON, even when i press Kill in MAX it doesnt changes.

i run all my test and able to run the servo using MAX only when activating the "servo on" signal to the servo drive manually.

p.s. the disable led is still not lit on any of the axis of the umi, but i dont care about this now, at least i can start testing the servo.

appriciate your help.

[Michelle_N]

Hi MotiM,

Can you go into further detail when you say the servo is not responding well. What does this mean? Does it keep going when you think the move should be complete? Is it acting erraditcally or inconsistently from one move to the other. Have you tuned your servo?

If not, take a look at these documents:

KnowledgeBase: A Simple Method for Motor Tuning
http://ae.natinst.com/operations/ae/public.nsf/webPreview/806F6F0B775FAF32862572FA0052F2AB?OpenDocument

Developer Zone Tutorial: Understanding Servo Tune
http://zone.ni.com/devzone/cda/tut/p/id/2923

KnowledgeBase: Unable to Tune a Servo Motor
http://ae.natinst.com/operations/ae/public.nsf/webPreview/19668AB2D4997F3D86256E940082F1EF?OpenDocumentkil

Can you give me more detail on what the servo on signal does on  your drive?

Message Edited by Michelle_B on 12-18-2008 04:10 PM

[M0Reng]

Hello Michelle,

Thank for your reply.

actually i didnt do anything about tuning the servo because i read here in some post in the forum,

that when i set the servo to "P-command" i dont need to set something in the servo tune in MAX...

its probably not right...

Thank you for the links about the servo tune, i'll read and test it now.

I'm using Yaskawa servo motor with Sigma FSP servo drive, i put it in Position command mode.

please see the attached image with all the setting in MAX (if you open it in microsoft paint, you can scroll it down like word document..)

Hereunder more details about the problem:

1.  when i'm using 1d interactive for simple move, the servo is run well, no problems,

      the count is ok, the servo stop exactly in the position he should be.

     This is true as long as the velocity is  1125rpm or under.

     The problem:  when i set it to 1150rpm and click start, the servo is rotate and imidiatelly stop, its looks like the servo got cough,

     there is some delay of some miliseconds and it rotate again for few steps and stops.

     when i'm looking at 1D interactive- Misc. Plot, i see the velocity is 1/4 of the velocity i set to this move.

     if i set the velocity to 1000rpm, the servo is run at 250rpm...

      its something with ratio of 1/4..   So, i think that its encoder problem, or something wrong in the setting

      cause i set the "Stepper steps per revolution"  = 8192 and "Stepper counts per revolution"  = 8192 also,

      where i know that it should be :

       "Stepper steps per revolution"  = 2048 and "Stepper counts per revolution"  = 8192

       But if i set it like this, the servo is never go to the position i command him.

2. About the "Servo -On" signal, attached the servo drive wiring, the servo on is a signal that anable the drive,

    when the servo on is activated the led screen on the servo drive displays "run" and the shaft has holding torque.

    The problem here is not with the servo on signal, that works fine, as you can see in the attached image, the servo on is activated using a relay, so for now i'm activatig it manually, when i want to start move in MAX, i turn on the "servo on" signal,

the servo drive is on, display the "run" and ready to recieve the "step","dir" commands, and it works.

 The problem that the Axis/Enable signal in the UMI7774 need to activate the relay that activate this "Servo on" signal,

and currently the Axis/Enable signal is always ON, even when i press "Kill" in MAX the Enable signal is still ON and never changes to off,

that is why i can activate the "servo on" signal using the Enable signal on the axis.

I'm using:  Widows XP proffesional sp3, LabVIEW 8.6 , MAX 4.5, NI-Motion 7.7, Motion assist 2.3,

 PCI -7344, UMI-7774,  Yaskawa servo motor and Servo Drive Sigma FSP,

here is the link to it :

http://www.yaskawa.com/site/products.nsf/products/Servo%20Amplifiers~fspsigma.html?openDocument&seq=...

Thanks for your reply,

MotiM

Message Edited by MotiM on 12-19-2008 02:00 AM

[Jochen]

Hi,

I think I can help you  with question #1:

I have just been working with some Yaskawa drives and I have run into a similar issue as you did (limited velocity). The reason for this issue is the limited bandwidth of the step input of the Yaskawa drive. The limit seems to be in the 150 kHz range and that's exactly the frequency that you reach when you go beyond 1100 rpm.

I have talked to Yaskawa about this issue and the solution that they came up with is electronic gearing. The Yaskawa drive supports gear ratios between the pulse input and the internal position control. E. g. you could set a gearing ratio of 1:3 to reach the 3000 rpm velocity range. Please check with Yaskawa how to set a gear ratio. Ynother option is to reduce the resolution of the position feedback signal. This should also be possible in the drive's settings. Please note, that both methods reduce the physical position resolution.

Concerning the mismatch between real velocity and commanded velocity you should try in 1D interactive how many steps you need to generate to rotate the axis by exactly one revolution. This value should be entered  as the steps/rev value.

I'm a bit in a hurry, so I'm sorry, that I can't take care of your second question, too.

Regards,

Jochen Klier

National Instruments

[M0Reng]

Hello Jochen,

thanks for your answer, that help.

i know how to use the servo drive and i set the electronic gearing to 1:4,

but now, as you write in your post, i have only 2048 counts/rev instead of 8192 counts/rev

and i need to see if 2048 counts/rev is good enough for the accuracy of the moving object that i need to test.

the servo is connected to gear with ratio of 1:10.

another thing, now i can run the servo for speed >3500rpm, but for high speed there is mismatch between the position in the command to actual position where the servo stop.

Thanks again for the answer, its really help to solve the problem quickly.

MotiM