Umi 7774

[Fernandes]

I connected the analog out 3 and 1 of Control connector to the + Ref in and - Ref in of AMC b25a20ac, respectively. See the Figure 3-12. Sinusoidal Commutation Wiring Diagram of UMI-7774 user manual. Is it correct?

Thanks

[Fernandes]

Hi,

I connected the Gnd, Index, Ch A, +5V and Ch B , of the incremental encoder HED 5640 this way:

Encoder                  Feedback connector of UMI-7774

Gnd                          pin 17

Ch index           pin 3

Ch A      pin 1

+5V           pin 4

Ch B                         pin 2

In the Interactive section of MAX, nothing happens with the counts of encoder when i move manually the shaft of the motor, that is connected to the encoder hed 5640.

I made a circuit with the ci 7404, to provide Ch A-, Ch B- and Index- . The connections:

Encoder                  Feedback connector of UMI-7774

Gnd                          pin 17

Ch index                 pin 3

Ch index-                pin 16

Ch A                         pin 1

Ch A-                       pin 14

+5V                          pin 4

Ch B                         pin 2

Ch B-                       pin 15

Does not works too. All leds of Axis 1 are ON. and the switches LIMIT LED, FAULT and ENABLE are in ACTIVE LOW position.

What can be the problem in my situation? I already tried to change the encoder and tested the continuity pin by pin of the connections described above and its ok.

Thanks.

[Fernandes]

Hi,

I connected the Gnd, Index, Ch A, +5V and Ch B , of the incremental encoder HED 5640 this way:

Encoder                  Feedback connector of UMI-7774

Gnd                          pin 17

Ch index           pin 3

Ch A      pin 1

+5V           pin 4

Ch B                         pin 2

In the Interactive section of MAX, nothing happens with the counts of encoder when i move manually the shaft of the motor, that is connected to the encoder hed 5640.

I made a circuit with the ci 7404, to provide Ch A-, Ch B- and Index- . The connections:

Encoder                  Feedback connector of UMI-7774

Gnd                          pin 17

Ch index                 pin 3

Ch index-                pin 16

Ch A                         pin 1

Ch A-                       pin 14

+5V                          pin 4

Ch B                         pin 2

Ch B-                       pin 15

Does not works too. All leds of Axis 1 are ON. and the switches LIMIT LED, FAULT and ENABLE are in ACTIVE LOW position.

What can be the problem in my situation? I already tried to change the encoder and tested the continuity pin by pin of the connections described above and its ok.

Thanks.

[Highland_Controls]

The UMI-7774 cannot take single ended encoders, as stated in the manual.  Here is an example of how to build a simple bias circuit, though.

The drive is doing trapezoidal commutation using the halls, and is not capable of sinusoidal commutation from your controller.  You should connect the analog out and analog ground to the reference inputs of the drive.

[Fernandes]

Hello Highland,

I tried to appIy the example that you sent to me, but i had not sucess. So, I made a circuit to provide A-, B- and Index- signals by using opamp (CI UA-741) configured like inverter. Please, see the attachment. Unfortunately, it does not work too. Any idea what can I do? I provided the channels A, A-,B,B-,Index, Index-, +5V, Gnd , like a differential encoder, to the UMI-7774.

The last solution, is to buy a differential encoder. I took a look at web and found one. Please, see the attachment. I would like to know if this differential encoder is compatible with UMI-7774.

Thanks for all,

Fernandes. 

[Highland_Controls]

What motion controller are you using?  Is it configured properly?  Can you connect an oscilloscope to the encoder inputs to make sure you are getting the proper signals?

[Fernandes]

My controller is a PXI-7350, that is connected to the UMI-7774. I'm using these devices to control a Brushless DC motor.

So, according to the encoder manual, the channels A,B and Index have ranges between 0,4V and 2,4V. The CI 741 are inverting the signals, but the encoder are not working properly. I'm using a Multímeter to do this. Do you like better i use an osciloscope? What is the form to read the signals A,B, Index by using a multimeter or osciloscope? "black" probe in the ground and the "Red" probe in channel A (for multímeter)?

When I do this configurantion to read Channel B, for example, the reading in the display varies between 0,1 and 0,14V...What should happen?

Thanks

[Highland_Controls]

Are you using the pull-up resistors on the encoder, as shown in the encoder manual?

[Fernandes]

Hi,

How the encoder manuaI say: "...2,7K ohm (+-10%)...", I`m using resistors of 3K ohm because i could not find 2,7K ohm resistors to buy.  Do you think can be this?

[Fernandes]

I read the Channels A and B with an Osciloscope and the result was like the manual describes, excepting the amplitude range that was different of 0,4 and 2,4V (is it the real operation range or maximum range?). So, at the moment that i turned on the inverter circuit, immediately the amplitude signals of A and B channels were reduced to almost zero (0) V.

Conclusion, I really have to buy a differential encoder to work with UMI-7774. Am I correct? I found a diiferential encoder at web and i would like to know if it is really compatible with UMI-7774. Please, see the attachment.

Thanks for the attention.