How do I connect UMI 7772 with ECMD 275 amplifier (from EC Motion)

[steffi.kono]

Hi,

I have connected the UMI 7772 to the ECMD 275 amplifier from EC Motion to operate a stepper motor, but it`s not working. I connected the analog output signal from the control connector of the UMI 7772 to the Puls+ of the ECMD 275 and according to this the analog output ground to the Puls-. Furthermore I connected the Step (CW) of the UMI to the Direction+ of the ECMD and Dir (CCW) to Dir-, Fault + of the UMI to Ready+ of the ECMD and Fault- to Ready-.

Does anybody know if I can connect the ECMD to an analog output signal? Or does anybody have an idea what the mistake is?

Thanks to everybody!

Steffi

[Jochen]

Steffi,

I don't know the ECMD 275 amplifier but your wiring looks a bit strange. Which NI-Motion board are you using? The UMI-7772 can be connected to NI 7330, 7340 and 7350 devices.

In general the analog outputs are used to control servo motors but as you are using steppers I would expect a wiring similar like that:

UMI         --->    ECMD
Step (CW)       Puls+
Dir (CCW)       Dir+     

Please make sure that the UMI is powered and that your NI motion control board is initialized. If you can't find a solution, please provide a link to the datasheet of your amplifier.

Best regards,

Jochen Klier
National Instruments Germany
 

[steffi.kono]

Hi Jochen,

thanks for you answer! Unfortunately there is no datasheet of our amplifier in the Internet. But I know that the "Puls" needs a 5V TTL / frequency signal and the "Direction" needs 5V DC. I put a 5V square signal (analog output) via LabVIEW on the amplifier and the motor is running! So the problem is at the UMI 7772, I don`t know which exit provides a frequeny signal. The UMI is powered and the board is initialized! Maybe you know where I get the corresponding signal? I tried your advice with Step (UMI) to Puls (amplifier), but it´s not working.

We have the PCI 7330 Motion Board.

Thank you very much,

Steffi

[Jochen]

Steffi,

I have just realized that you are also in contact with one of our Applications Engineers via telephone. Please call in again if you can't figure out a solution.

Jochen

[Buechsenschuetz]

> But I know that the "Puls" needs a 5V TTL / frequency signal and the "Direction" needs 5V DC.

The direction input usually is fed with a constant level signal (unless you want to change the direction of turning), this signal usually is 0V for one direction and +5V for the other direction.

> So the problem is at the UMI 7772, I don`t know which exit provides a frequeny signal. The UMI is powered and the board is initialized! Maybe you know where I get the corresponding signal? I tried your advice with Step (UMI) to Puls (amplifier), but it´s not working.

The UMI boxes are rather passive devices and do not create any signals, they just feed through what the motion control board supplies to them. So if you connect the STEP output of UMI to the PULSE (or STEP) input of your amplifier, this should work - basically.

But it also depends on the software settings of your motion controller. Usually the best way to start is to use the MAX software. Make sure that (for a start) the outputs of the motion controller are set to "stepper motor", and that you have an "open loop" control. If the board is set to "closed loop" it expects a feedback signal from an encoder - if this is not present it will stop motion sooner or later, depending on the "following error" (i.e. number of allowed missing encoder pulses) setting.

[steffi.kono]

Hi,

thanks for your answer. Unfortunately it`s still not working. We already tried it with MAX and made the settings you mentioned, but nothing happens. We expanded NI Motion Devices, then our PCI 7330 controller and tried to test it with 1-D Interactive. MAX is running (counts steps in Current Trajectory Data), but the motor isn`t moving. There is no error in MAX. At Axis Status there are the following LEDs red: Limit Switch is active and Home Switch is active. Does that matter??? Can we change that?

Shall we put anything in Cycle Mode? Or can we test it anywhere else in MAX? We don`t understand it as the motor is running with the NI USB 6251 (and a LabVIEW program).

Thanks for your help. I could also scan the datasheet from the amplifier of the motor, but I guess we all know which signals are needed.

Thanks,

Steffi

[Buechsenschuetz]

> At Axis Status there are the following LEDs red: Limit Switch is active and Home Switch is active. Does that matter???

Yes, it DOES matter. If the motion controller thinks that one of the limit switch is active, it does not perform any motion towards that (sometimes imaginary) limit switch. If it thinks that BOTH limit switches are active, consequently it does NOT perform ANY motion.

> Can we change that?

Yes. You can set the polarity of the limit switches to the opposite value, or disable them completely (if you do not plan to use any limit switches, in a rotary motion system, for example, this usually is not necessary).

In general, as mentioned above, NONE of the limit switch indicators should light up if you did not connect any switches. Obviously LabView has an initialization setting for the limit switches which is different from that in MAX.

You don't have to care about the HOME switch indicator too much. You can change the polarity or disable it, too, if you do not use any reference position in your motion system. (It is strictly recommended to use a reference position and a sensor on that position for practical use in case the system gets out of sync - there is no way the motion controller can check actual position of your system if there is no feedback via a HOME switch or a - rotary or linear - encoder.)

[Buechsenschuetz]

See

http://zone.ni.com/devzone/cda/tut/p/id/4465

for more information about what limit switches are for in motion control.

[steffi.kono]

ok, now there are only green LEDs left on MAX: ) Everything seems to be ok with Max now, it does the move and there is no error or red LED anymore. BUT the motor is still not moving... The fault and disabled LED are red on both axis on the UMI, FWD, HOME and REV are orange. Do you have an idea why? I could change the polarity of the switches on my UMI again (then there is only the disabled LED left), but I guess that doesn't matter, the motor isn't moving in both cases.

There is also a red LED called "interlock" on the UMI (beneath global stop).

I'm sorry, I don't have the slightest idea what I'm doing wrong.

Maybe you have an idea again.

THANK YOU!!

[AnalogKid2DigitalMan]

Steffi:

Here's your manual, straight from the manufacturer's website:

http://www.ec-motion.com/pdl/Handb_ECMD275_e.pdf