MCF8316AEVM: MPET IPD Fault does not dissolve

Hi Tanaka-san, 

Our team will review your request and aim to provide a response by end of the week 

Best Regards, 
Andrew 

Hi Tanaka-san,

Apologies for the delayed response.

1. Could you please help ensure that the potentiometer (R4) is turned all the way clockwise? This is to ensure that the SPEED pin sees 0V initially.
   1. The default setting configures speed input to be Analog mode. Therefore, if the on-board potentiometer is putting some voltage on the SPEED pin, the MCF8316A will immediately attempt to run MPET on power up or after restoring default settings. If MPET runs before MAX_SPEED is configured, it will fail.
2. After restoring default values (step 4 in your post above), the algorithm status should be "MOTOR_IDLE". You may need to click on the clear fault button.
3. When running MPET or when the motor is spinning, please turn off the "Auto read motor status" and "Auto read motor fault" buttons. This is due to an I2C bug in the MCF8316A device. This will be fixed in the next device revision (MCF8316B)
4. Could you please also help provide the motor datasheet or the following information of your motor?
   1. Rated voltage
   2. Rated peak current (continuous)
   3. Maximum speed (in RPM or electrical Hz)
   4. Number of poles
   5. Motor Resistance
   6. Motor Inductance
   7. Motor BEMF constant

What kind of load is the motor spinning? Is it air, liquid? Is the load dynamic?

Thanks,
Eric C.

Hello

The procedure that I tried this time.
1.First. I ensured that R4 is turned all the way clockwise.
2.After restoring default values (step 4 in my post above), the algorithm status was "MOTOR_IDLE".
3.I click on the "Auto Read Fault Status and Auto Read Motor Status" button of this GUI.
D2 does not turn on and MPET PID Fault is green indication.
4.I turned off the "Auto read motor status" and "Auto read motor fault" buttons.
5.I click "NEXT" button. Move "Device and Pin Configuration" menu.
6.I select "Analog Mode".
7.I click "NEXT" button. Move "Motor Parameters" menu.
8.I input "2pole pairs and 3900rpm" and click "Use Calculated Value" button.
9.I select "ILIMIT 5A". I click "NEXT" button. Move "Start-up into Closed Loop" menu.
10.now D2 does not turn on.
11.Step B in "Apply a nonzero sp command", I turn R4 all the way counterclockwise.
12.but the motor didn't spin. then D2 turn on.
13.I click on the "Auto Read Fault Status and Auto Read Motor Status" button of this GUI.
In Fault Status, only MPET IPD Fault is red indication.
Motor Status is MPET Fault indication.

The kind of load is air and static load.

motor information

a.Rated voltage 24V
b.Rated peak current (continuous) 420mA
c.Maximum speed (in RPM or electrical Hz) 3900rpm
d.Number of poles 4 poles
e.Motor Resistance 18.5ohm
f.Motor Inductance 7.83mH
g.Motor BEMF constant Maybe 19.6/0.42=46.6mNm/A

Rated Torque 19.6mNm

Regards,
S Tanaka

Hi Tanaka-san, 

Appreciated on the additional details. 

Our team will review the info further and aim to provide a response on timeline & next steps. 

Best Regards, 
Andrew 

Hi Tanaka-san,

It looks like your motor has a fairly high resistance and inductance. It's possible that the MPET IPD current threshold is too low.

Could you please try increasing the MPET_IPD_CURRENT_LIMIT by using the All Tuning Settings Page:

If 2.0A is still not sufficient, you could try using the regular IPD threshold for MPET by disabling MPET specific IPD parameter:

If MPET is still not able to complete successfully, you could try entering all Motor Parameters manually before setting a non-zero speed command:

After these motor parameters are entered, when you provide a non-zero speed command, the MPET will still run to estimate the mechanical parameters and determine the appropriate Speed loop Kp and Ki to use:

Since you mentioned that your motor's rated peak current (continuous) is 420mA, I would recommend starting by setting the ILIMIT and OL_ILIMIT to ~1A in the beginning:

Regards,
Eric C.

Hello

I wrote wrong motor information.
e.Motor Resistance 18.5ohm/2 = 9.25ohm
f.Motor Inductance 7.83mH/2 = 3.92mH

However, I try this reply.

I telework in early this week.
When I will go to my office next, I try it.

Regards,
S Tanaka

Hi Tanaka-san,

Thanks for the update. Please post back when you get a chance to try again with different MPET IPD settings or manually entering the motor parameters.

Regards,
Eric C.

Hello

I increased MPET_IPD_CURRENT_LIMIT, but was not improved.
I increased IPD_CURR_THR, but was not improved.
I try entering all Motor Parameters manually before setting a non-zero speed command.
As a result, the motor spin, and MPET Fault dissolved.
Thank you for advice.

Basic Controls>>Control Configurations>>Faster deceleration.
A description of step C is the same as step B.
I want to know the right contents of step C.


Regards,
S Tanaka

Hi Tanaka-san, 

Thanks for the additional info - our team will take a closer look at this and aim to provide a response shortly on next steps and timeline 

Best Regards, 
Andrew