BR063

Encoder Input to control Servo RPM

36 posts in this topic

I put that number in as a reference for now. I am not sure what it will be at this point. My encoder monitoring my spindle RPM is an Omron E6C2-CWZ6C-1000P/RM. The servo motor and drive are R88M-K75030H-BS2 and R88D-KT08H. At this point I am not even sure how many pulses per rev is on that motor and drive. 

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From memory that servo pulse inputs has a default setting of 10,000 pulses per motor rev.

This is set in the drive via parameter Pn008.

Since the maximum pulse train output of the CP1L is 100kHz this will allow you to rotate the the servo up to 10 revs/second [600 revs/min].

If you need more speed then Pn008 must be set to a lower value.

I think you have plenty of info to move forward. Good luck.

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Much appreciated. Thanks for all the help.

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I have all my components wired in. Did a Servo test run and the servo works. I see my pulse output on the PLC lights flickering but the Servo doesn't run.

I had to wire in an output to activate the Run on the servo to pull in the brake. Servo doesn't seethe pulses. What am I missing?

I am not sure how to monitor the high speeds Output 0, (100.00, 100.01) real time in CX-Programmer.

I wired it up the same as the attached drawing with the exception of the fact that the PLC in the drawing is Sourcing outputs so I have:

CP1L-M60DT-A to R88D-KT08H with R88M-K75030H-BS2 Motor

100.00 to Pin 4-CW (Note: Not using Shielded twisted pair for these)

100.01 to Pin 6 -CCW

100.04 to Pin 29 RUN

-24V to Pins 10 BKIRCOM , 8 and 9 (Do I need to connect to Pin 25 or 33?)

+24V to Pins 1,2,7

I am not using Origin Search so no other connections on CN1

I will try -24V to Pin 33.

Would appreciate any help.

R88M_KT08.cxp

I571-E1-05 598.pdf

Connecting CP1H-X40DT1-D.pdf

I571-E1-05 135.pdf

Edited by BR063

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Set up a rung for testing only using the SPED instruction with very slow frequency [Say 1 Hz].

As the SPED instruction is configured for PULSE + DIRECTION, with this rung enabled you should see one output flashing once per second [PULSE OUTPUT]

If you reverse direction with SPED the same output will flash once per second and the DIRECTION output will turn ON.

Now you know your program and PLC are operating as desired.

In the servo be sure you have defined PULSE/DIRECTION as the desired method of control in PARAMETER  Pn006 = 3.

Set Pn001 to 3 [Mode 2 = Speed control].

After cycling power on the servo you should be able to monitor pulse inputs from the PLC in the Servo in the MONITOR mode. Pn528 = 3.

Once you have "seen" command pulses in the Servo you have confirmed that wiring is good and can progress with next steps in your project.

 

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I have all my components wired in. Did a Servo test run and the servo works. I see my pulse output on the PLC lights flickering but the Servo doesn't run.

I had to wire in an output to activate the Run on the servo to pull in the brake. Servo doesn't seethe pulses. What am I missing?

I am not sure how to monitor the high speeds Output 0, (100.00, 100.01) real time in CX-Programmer.

I wired it up the same as the attached drawing with the exception of the fact that the PLC in the drawing is Sourcing outputs so I have:

CP1L-M60DT-A to R88D-KT08H with R88M-K75030H-BS2 Motor

100.00 to Pin 4-CW (Note: Not using Shielded twisted pair for these)

100.01 to Pin 6 -CCW

100.04 to Pin 29 RUN

-24V to Pins 10 BKIRCOM (Do I need to connect to Pin 25?)

+24V to Pins 1,2,7

I am not using Origin Search so no other connections on CN1

Would appreciate any help.

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I did not realize that my output mode was set to Pulse  + Direction. I guess it should have read #0010 for CW/CCW rather than #10 on each of the SPED commands. That is why I thought it would work with the default settings. If so that is my mistake in the interpretation. If I change this to read #0010 it should work with the default settings. Or should it be #0000 0000 0000 for CW and #0000 0001 0000 for CCW? Not sure

Edited by BR063

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#0100 = Output Method = Pulse+Direction, Direction = CCW, Mode = Continuous.

#10 should be the SAME as #0010 Output Method CW/CCW, Direction = CCW, Mode = Continous.

So your SPED command should be sending continuous pulses to the servo in the CCW direction.

Check your wiring and use the monitoring function on the servo to confirm that pulses are being received from the PLC.

 

Edited by BITS N BYTES

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Thanks I'll work on it over the weekend.

Everything checks out as it was my wiring after all. Had 3 and 5 instead of 4 and 6 plugged in on -24v. Noticed it right away. Too much on my mind I guess. 

Question: Does the ACC insruction work with the SPED?  Rapid up and down would be nicer with a ramp up of the RPM.

Sorry just read back and I have to set those parameters in the servo drive.

Edited by BR
Answered my own question

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In this same project I control a 3HP motor that drives my spindle through a Gearbox. It now has an encoder attached to it so that the servo drive can synchronize feed rate with its RPM.

Works great!

I am trying to stop the VFD spindle at a radial position. I used 3.0 Hz to rotate to a proxy flag and change speed to the lowest possible setting (0.2 Hz) and stop at the next flag. It works okay 9 times out of 10. The accuracy is good enough, my deceleration and acceleration times are set to there lowest values. Is there a way to use encoder that is wired into the 0.00 and 0.01 as well as my proxy flag to accurately stop this motor? I figured the proxy setting accuracy would be enough but the motor is stiffer than usual because of the gearbox. I know the CP1L can control an inverter but extra hardware is needed and I am not sure if it can control a both a servo and inverter motor at the same time.

At present i will try adding a second proxy to flag if it over shoots the 1st proxy edge and have the motor reverse and retry until both proxies are on after edge detection. I am pretty sure that will work but don't like seeing a spindle search for its home over and over again.

Forgot to add the Spindle motor has no brake as it never needed one.

Edited by BR063
No Brake on spindle Motor

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The CP1L has Inverter Positioning functionality using either speed commands via ModBus RTU or Analog outputs. This feature is covered in the Operation manual W516-E1-01 CP1L-EL_EM under advanced functions. The VFD's covered in this application were from Yaskawa, Since OMRON has ceased their relationship with Yaskawa I do NOT know if this functionality still remains with other VFD models.

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