BOOST-DRV8711: Stepper motor card with SM2563C40B41 stepper motor

Hi Neeraj,

Thanks for your post.

The datasheet for the SM2563C40B41 stepper motor indicates the following electrical specifications.  Bipolar winding 4 A rated current / phase, 0.52 Ω DCR, and 2.4 mH / phase coil inductance. Based on this specification the DRV8711 is compatible for driving this stepper with no issues. If the BOOST-DRV8711 hardware was used the MOSFETs should be sufficient to drive the 4 A rated current per coil. What was the VM supply used?

ArTzy said:

DRV-8711 stepper motor card is intermittently able to rotate this motor with STALL signal active.

STALL detection is report only and does not affect the motor drive. STALL detection is not the cause for intermitted rotation. There should be some other issue in the system. Please share the coil current waveform for analysis.

ArTzy said:

SM2563C40B41 stepper motor is giving humming sound ramping up as per ramp up logic to increase the speed where motor PWM frequency capped at 100KHz to prevent the mechanical damage to motor bearing written by us but without any movement of motor rotor which due to which this motor winding getting heat up after repeated trials very fast.

As per the speed v. torque plots for this stepper motor its torque output falls below 50 % at 3 kHz STEP rate with full-step mode. This stepper motor is likely to stall from around 5 kHz step rate or higher because of low torque. Under this condition the motor coils will over heat assuming the coil current was properly set at 4 A. This is the expected behavior of the stepper motor and nothing pertaining to the DRV8711 driver. What was the step mode configured in your testing specifically with 100 kHz step rate. 

ArTzy said:

• DRV-8711 stepper motor card is able to give the drive to the motor by using STM32F429ZIT6, we have written the code as per guidelines given in the BOOST-DRV8711_FIRMWAREv1.11 given inside slvc575b.zip. We have also referred SLVC500 — DRV8711 Software to write our firmware.
• The above mentioned code doesn't clarify the implementation of the reset procedure of the DRV8711 chip.

Please refer to the datasheet - see below.

ArTzy said:

Settings for the CTRL & TORQUE register inside DRV8711 need to be written each time before giving a PWM signal . In this condition, DRV8711 gives driving current to power MOSFET already mounted on BOOST DRV8711 kit.
But this is not acceptable, if we give only PWM signal but without these settings, DRV8711 doesn't give driving current to power MOSFET already mounted on BOOST DRV8711 kit.

Are you referring to STEP pulse input as PWM? It is not required to setting the CTRL and TORQUE every time before issuing STEP input. However if the device goes through a sleep and wake cycle or RESET the registers will assume the default values mentioned in the datasheet. The code must be written such that the device does not go to sleep or reset between step pulses. Every time the device is RESET or waken up from sleep the registers must be configured to the desired setting. 

ArTzy said:

Also if we reconfigure all the registers repeatedly,clearing all errors in STATUS Register (Address = 0x07) even then DRV8711 refuses to give driving current to power MOSFET already mounted on BOOST DRV8711 kit.

If you RESET the device then all registers will revert to default values. Under normal operation no errors should happen so a reset would not be necessary. While the output drive is not active after reconfiguration what is the STATUS register read out? Certain faults can render the outputs HiZ. See datasheet. 

ArTzy said:

When ENBL bit =0 inside CTRL Register (Address = 0x00) then  DRV8711 gives driving current to power MOSFET already mounted on BOOST DRV8711 kit. Otherwise  ENBL bit =1,  DRV8711 refuses to give driving current to power MOSFET already mounted on BOOST DRV8711 kit. This is opposite of what is mentioned in the datasheet.
Repeated trials revealed that there is danger of permanent electrical damage to windings of motor & mechanical damage of motor bearings to proceed in the above manner.

This is not possible. When ENBL = 0 the default state there won't be any outputs from the driver. It is likely the SPI transactions were incorrect format. 

ArTzy said:

When we read back all the registers, registers give wrong or corrupted values even after following guidelines given for SPI transactions in the DRV8711 datasheet.   

This also points to an issue with the SPI format used. What MCU was used to driver - was it the TI suggested Launchpad or another external MCU? The SPI frame format must exactly follow the format mentioned in the datasheet. 

ArTzy said:

Kindly give us comprehensively written example source code in embedded c to validate the input signal waveforms for SPI & PWM which we can port across all of our device platforms.

The BOOST-DRV8711_FIRMWAREv1.11 is meant for a specific Launchpad. Additionally SLVC500d.zip is a good reference as it is proven in the currently shipping EVM. The complete schematic for the DRV8711EVM can be downloaded from the EVM webpage, https://www.ti.com/lit/zip/SLVC594. The C source code was written for the onboard MSP430F1612 MCU.

What are your device platforms MCU used? The low level functions must be adapted to match your platform. Thank you.

Regards, Murugavel    

Dear Murugavel4637,

Please! find the detailed answers given below:  

GOOD NEWS: I m able read & write the all settings correctly to DRV8711 using SPI core inside Current MCU : STM32F429ZIT6 

1. VM supply used : 24VDC @ 5 amperes.

2. STALL detection is report only and does not affect the motor drive. STALL detection is not the cause for intermittent rotation. There should be some other issue in the system. -> That is fine, we will share the coil waveform on later stage once we are able to rotate the motor.     

3. As per the speed v. torque plots for this stepper motor its torque output falls below 50 % at 3 kHz STEP rate with full-step mode. This stepper motor is likely to stall from around 5 kHz step rate or higher because of low torque. Under this condition the motor coils will over heat assuming the coil current was properly set at 4 A. This is the expected behavior of the stepper motor and nothing pertaining to the DRV8711 driver. What was the step mode configured in your testing specifically with 100 kHz step rate. 
-> By the time of your reply, i have already understand this point. To avoid the heating issue, i m currently testing at around 1 Amp ( 0x17) TORQUE. i have tested this motor earlier with F2BFD400P100 Driver at 1/64 microsteps @64x200 = 12800 pulses per rev at current capped around 2.7Amps. 
i want to continue with these settings. Kindly! suggest basic PWM frequency using which motor can smoothly complete the rotation without being getting stall for at-least starting from 13 RPM to maximum 600 RPM.

4. By now, i have clearly understood basic RESET procedure of DRV8711 chip. 

5. Are you referring to STEP pulse input as PWM? It is not required to setting the CTRL and TORQUE every time before issuing STEP input. However if the device goes through a sleep and wake cycle or RESET the registers will assume the default values mentioned in the datasheet. The code must be written such that the device does not go to sleep or reset between step pulses. Every time the device is RESET or waken up from sleep the registers must be configured to the desired setting. 
-> Yes, i m referring STEP pulse input as PWM. i m not resetting or putting sleep and wake cycle on DRV8711 chip after step pulse, but still this is happening.   

6. This is not possible. When ENBL = 0 the default state there won't be any outputs from the driver. It is likely the SPI transactions were incorrect format. This also points to an issue with the SPI format used. What MCU was used to driver - was it the TI suggested Launchpad or another external MCU? The SPI frame format must exactly follow the format mentioned in the datasheet.
-> i m able to solve this problem after corrections in settings of SPI core. 

now, i need the settings of all registers required to rotate above mentioned stepper motor from 13 rpm to 600 RPM or at max 625 RPM. 
currently, i m testing the motor at  around 100 KHz PWM (but this can be wrong way), Please! advise minimum PWM required to start this motor. 

Please! treat this as urgent help. 

THANKS WITH REGARDS 

NEERAJ GUPTA 

Hi Neeraj,

Thanks for the update.

NEERAJ GUPTA said:

I m able read & write the all settings correctly to DRV8711 using SPI core inside Current MCU

This is good to know. 

NEERAJ GUPTA said:

To avoid the heating issue, i m currently testing at around 1 Amp ( 0x17) TORQUE.

Reducing the IFS (full-scale current) definitely will help reduce heating. However it will also reduce the torque output of the motor. The motor is specified for 4 A per phase operating current for achieving full torque output up to 1 kHz STEP rate. 

NEERAJ GUPTA said:

PWM frequency using which motor can smoothly complete the rotation without being getting stall for at-least starting from 13 RPM to maximum 600 RPM.

600 RPM means 10 rev/s or 200 x 10 x 64 = 128 kHz STEP rate at 1/64 microsteps. This translates to 2 kHz in full-step (FS) mode. Per the motor's speed vs. torque the torque falls to 40 % level at 2 kHz FS. If you test with 1 A this would mean way lower torque, highly likely the motor would stall.

The desired starting speed was 13 RPM. This would translate to 200 x (13/60) x 64 = 2.773 kHz STEP rate at 1/64 microsteps, i.e. 43 Hz in FS mode. This shouldn't be an issue because the torque is at the max. level in the plot at this frequency. 

In order to achieve 600 RPM you'll have to implement a trapezoidal ramp up motion profile where the STEP rate increases over a short period of time rather than jumping directly to 128 kHz with 1/64 microsteps. Start the motor at minimum speed 2.8 kHz and ramp to 128 kHz. Starting at 128 kHz most stepper motors won't be able to keep up. We have this motion control implemented in our EVMs. See attached documents and pseudo C code for the trapezoidal motion control with acceleration and deceleration implementation.

5661.Stepper Motion Control.pdf 7737.Motion profile C source code.pdf

NEERAJ GUPTA said:

-> Yes, i m referring STEP pulse input as PWM. i m not resetting or putting sleep and wake cycle on DRV8711 chip after step pulse, but still this is happening. 

If everything else looks correct and this still happens it suggests either the VM voltage had momentarily dropped below UVLO threshold. Can you read STATUS register value after this incident and share for analysis?

NEERAJ GUPTA said:

i need the settings of all registers required to rotate above mentioned stepper motor from 13 rpm to 600 RPM or at max 625 RPM. 
currently, i m testing the motor at  around 100 KHz PWM (but this can be wrong way), Please! advise minimum PWM required to start this motor. 

The following register settings and sequence are recommended after power on and wake up from sleep:

1. Wait at least 1 ms (tSLEEP). 
2. OFF register leave default values.
3. BLANK register either default value or set ABT = 1.
4. DECAY register, set DECMOD to 101: Use auto mixed decay at all times, rest default.
5. STALL register, set based on application needs.
6. DRIVE register, all defaults okay, OCPTH = 00b.
7. TORQUE register as per IFS current requirement. SMPLTH default.
8. CTRL register, keep ENBL = 0b and change MODE to 1/64, EXSTALL default, ISGAIN as per IFS current, DTIME default.
9. CTRL register, logic OR ENBL = 1b to enable outputs.

After configurations completion, STEP input can be started using a trapezoidal motion profile to start from minimum speed 2.8 kHz and ramp to desired speed or a max. 128 kHz. 

Regards, Murugavel 

Using the following calculations given below:

Using ISGAIN = 10 as the default for 0.5–4.0 A.

• With R_SENSE = 0.05 Ω, ISGAIN = 10 gives:

  • Current per TORQUE LSB ≈ 0.021484375 A (≈21.5 mA/LSB)

  • Maximum IFS with TORQUE = 255 ≈ 5.48 A (so 4 A is well inside range).

• TORQUE for common currents (approx):

  • 0.5 A → TORQUE ≈ 23 (0x17)

  • 1.0 A → TORQUE ≈ 47 (0x2F)

  • 2.0 A → TORQUE ≈ 93 (0x5D)

  • 3.0 A → TORQUE ≈ 140 (0x8C)

  • 4.0 A → TORQUE ≈ 186 (0xBA)

i have applied the following settings on BOOST-DRV8711 evaluation kit given below: 

// settings for Torque register
G_TORQUE_REG.Address = 0x01;
G_TORQUE_REG.SIMPLTH = 0x01;
G_TORQUE_REG.TORQUE  = 0x8C;

// settings for CTRL Register
    G_CTRL_REG.Address     = 0x00;
    G_CTRL_REG.DTIME     = 0x03; //DEFAULT SETTING
    G_CTRL_REG.ISGAIN     = 0x01; //01: Gain of 10 -> Imax = 5.48 A balanced choice -> TORQUE LSB =(21.5 mA/LSB)
    G_CTRL_REG.EXSTALL     = 0x00; //0: Internal stall detect
    G_CTRL_REG.MODE     = 0x06; //0110: 1/64 step
    G_CTRL_REG.RSTEP     = 0x00; //0: No action
    G_CTRL_REG.RDIR     = 0x00; //0: Direction set by DIR pin. 

Important note: i have used calculation given by you in above as per RPM of motor, i m able to get PWM frequency as recommended by you. 

i have also used the guidelines in given in these 2 pdfs  

5661.Stepper Motion Control.pdf 7737.Motion profile C source code.pdf

Problem:Upto 400 RPM, SM2563C40B41 stepper motor is working smoothly but when same stepper crosses 400 RPM on upper side, motor begins to produce loud vibration & after sometime, it slows down & it gets unreasonably heat up. DRV-8711 also triggers Fault LED. 

So far i have tuned the settings highlighted in bold. Please! guide if any other settings going affect the motor rotation upto 600 RPM.

Please! again treat this urgent help needed. 

THANKS for your support

NEERAJ GUPTA

    

Hi Neeraj,

NEERAJ GUPTA said:

i have applied the following settings on BOOST-DRV8711 evaluation kit given below: 

// settings for Torque register
G_TORQUE_REG.Address = 0x01;
G_TORQUE_REG.SIMPLTH = 0x01;
G_TORQUE_REG.TORQUE  = 0x8C;

// settings for CTRL Register
    G_CTRL_REG.Address     = 0x00;
    G_CTRL_REG.DTIME     = 0x03; //DEFAULT SETTING
    G_CTRL_REG.ISGAIN     = 0x01; //01: Gain of 10 -> Imax = 5.48 A balanced choice -> TORQUE LSB =(21.5 mA/LSB)
    G_CTRL_REG.EXSTALL     = 0x00; //0: Internal stall detect
    G_CTRL_REG.MODE     = 0x06; //0110: 1/64 step
    G_CTRL_REG.RSTEP     = 0x00; //0: No action
    G_CTRL_REG.RDIR     = 0x00; //0: Direction set by DIR pin. 

What are the settings for the BLANK and DECAY? Were you enabling ABT in BLANK and using 101: Use auto mixed decay at all times for DECAY? Please confirm.

NEERAJ GUPTA said:

Important note: i have used calculation given by you in above as per RPM of motor, i m able to get PWM frequency as recommended by you. 

i have also used the guidelines in given in these 2 pdfs  

5661.Stepper Motion Control.pdf 7737.Motion profile C source code.pdf

Okay that's good. Thanks for the update. 

NEERAJ GUPTA said:

Problem:Upto 400 RPM, SM2563C40B41 stepper motor is working smoothly but when same stepper crosses 400 RPM on upper side, motor begins to produce loud vibration & after sometime, it slows down & it gets unreasonably heat up. DRV-8711 also triggers Fault LED. 

Based on your motor characteristics > 400 RPM the torque output of the motor will be < 50 % of the rated torque. Vibration was likely caused by insufficient torque output of the motor vs. load requirements. It could also be mechanical resonance which is your system dependent and outside the scope of the DRV8711 device related behavior. 

Can you share the coil current waveform either coil A or B, for < 400 RPM, and > 400 RPM when there is loud vibration and slowing down. Regarding heating up of the motor it is expected behavior of the stepper motor. When the motor is not running smoothly its BEMF drops significantly and all the power is dissipated via the coil I2R losses as heat. Running the stepper in this state should be avoided. What happens when the speed was increased further, for example 450 RPM or higher? Would be useful to get current waveform for these speeds as well. If the issue was mechanical resonance around 400 RPM you can skip that specific range of speeds to avoid resonance - this is the typical solution used in the industry for overcoming resonance related issues. You may want to search the internet for "stepper motor resonance and how to avoid it". 

DRV8711 triggers fault LED. Can you share the contents of the STATUS register readout when this fault was happening? This would help with the diagnosis along with the current waveform. Without current waveform it is impossible to understand what is happening in your application when the motor is vibrating at > 400 RPM.

Can you also try increasing the VM supply voltage from 24 V to 33 V or 36 V and see if you could drive the stepper motor to > 400 RPM? Increasing VM voltage will not impact stepper motor current because of the constant current drive from the DRV8711. If increasing VM solves the speed issue it means the VM 24 V was not sufficient to overcome the BEMF at > 400 RPM which is also known behavior of stepper motors. 

In one of your previous posts you mentioned, "i have tested this motor earlier with F2BFD400P100 Driver at 1/64 microsteps @64x200 = 12800 pulses per rev at current capped around 2.7Amps. ". But you did not mention at what step rates you tested. Did you test running 400 RPM to 600 RPM? Could you also capture the coil current waveform for > 400 RPM with this driver as well for comparison? 

Regards, Murugavel 

I m able to solve my problem by running motor from 400 to 600 RPM based on same settings just by decreasing the microsteps & configuring corresponding stepping frequency as per calculation given by you . Yes, i have tested running 400 RPM to 600 RPM above motor with F2BFD400P100 Driver, it was running very smoothly. Of course, i would like to share coil current waveform for > 400 RPM with this driver as well for comparison but i found that there is conformal protection coating over PCB of  F2BFD400P100 driver.

Now only question remaining,

1. Did i need to probe status register very time because when i read status register DRV8711 stops the drive to POWER MOSFETs.

Just answer this question . 

Many x Many x 1000 thanks for whole TI team to help to solve the problem. 

THANKS WITH REGARDS

NEERAJ GUPTA

i was just reading back the status register without any writing ,still DRV8711 drive stopping working. if i do not read at all from any register, then drive work correctly & follows the command. TORQUE register configured for around 3A when IS-GAIN 01: Gain of 10. Another problem after in depth testings reveals that when stepper motor rotated less than around 80 RPM, it rotates smoothly but DRV-8711 raises STALL LED gets "ON" when stepper motor rotated greater than around 80 RPM then STALL LED gets "OFF". 

Important point to note in whole exercise in whole testing: To rotate the motor smoothly, reading of any register has to bypass. 

i do not know how to proceed further but yes motor is rotating now. Please! advise ?

Hi Neeraj,

NEERAJ GUPTA said:

i was just reading back the status register without any writing ,still DRV8711 drive stopping working. if i do not read at all from any register, then drive work correctly & follows the command. TORQUE register configured for around 3A when IS-GAIN 01: Gain of 10.

For debug purpose, immediately after doing a STATUS read and the motor stops, can you read all the registers and send the values to us? We need to see which bit has changed. How is the hardware connection made between your MCU and the BOOST-DRV8711 board? Can you send a picture of this and wiring diagram or schematic?

I'm unable to reproduce this issue with an EVM. 

NEERAJ GUPTA said:

Another problem after in depth testings reveals that when stepper motor rotated less than around 80 RPM, it rotates smoothly but DRV-8711 raises STALL LED gets "ON" when stepper motor rotated greater than around 80 RPM then STALL LED gets "OFF". 

This is because the BEMF reading was going below the stall threshold in the STALL register when the motor is < 80 RPM. This tells me the stall detection is working well. You have to fine tune the stall detection settings such that it matches the stepper motor.

The default value of VDIV is BEMF/32. Depending on the stepper motor you may have to change this value. With low BEMF motors this should be set to BEMF/4. For noisy BEMF which some stepper motors may have the SDCNT value must be increased from the default value of 0. Likewise the default SDTHR is 0x40, this may have to fine tuned such that false stall detection does not happen. SMPLTH in the TORQUE register may have to be increased as well for some stepper motors. If stall detection is not required, you can set EXSTALL bit in the CTRL register. This setting will disable the internal stall detect and avoid STALL LED turning on.

Regards, Murugavel 

When reading the status bits from status register using SPI when STALL LED gets "ON". Then STD & STDLAT bits are found to HIGH each time, UVLO bits also get "HIGH" but only for very short duration, only when motor rpm is less than 80 RPM. But when RPM greater than 80 RPM , then these bits are "LOW". Again, it has been very difficult to obtain this information while debugging. Since motor refuses to run in most cases & also gives jerk even these bits are cleared to restart the motor. So, we need to bypass this reading to run the motor smoothly. Also there is humming sound coming from motor just like emitted by food mixer motor. whereas i have tested this motor with other well matured stepper motor driver, this motor is running silently. Please! advise.     

Hi Neeraj,

NEERAJ GUPTA said:

When reading the status bits from status register using SPI when STALL LED gets "ON". Then STD & STDLAT bits are found to HIGH each time,

Stall detection and reporting are for indication purpose only and does not stop the motor operation. A stall is detected when the internal stall count goes below the SDTHR in the STALL register. You may have to reduce the threshold. Regardless it is common for getting a STALL report at low speeds because of low BEMF voltage. This depends on the motor construction. This is why the DRV8711 supports external stall detection which can be done with an MCU ADC input and an algorithm. A STALL detection does with internal detection EXSTALL = 0 will not stop the motor. To avoid stall detection temporarily, you could set EXSTALL = 1. 

NEERAJ GUPTA said:

UVLO bits also get "HIGH" but only for very short duration, only when motor rpm is less than 80 RPM. But when RPM greater than 80 RPM , then these bits are "LOW". Again, it has been very difficult to obtain this information while debugging.

When an UVLO is detected the driver will not operate. This is built-in protection mechanism. An UVLO would be detected only if VM momentarily falls below the UVLO falling threshold. This indicates a power supply issue. You could observe the VM voltage with an oscilloscope, capture it when FAULTn pin goes low and share with us, this pin will go low at the instant UVLO is detected.

Reading STATUS register does not trigger UVLO falsely. I tried reading STATUS register several times with no issues using a DRV8711EVM. We cannot reproduce this issue.

The DRV8711 is a mature stepper driver as well. It is used by several customers world-wide since 2013, for more than a decade. Millions of these devices are used in many applications, no such false UVLO report. This is related to your setup. Please try with a different power supply.

NEERAJ GUPTA said:

Also there is humming sound coming from motor just like emitted by food mixer motor. whereas i have tested this motor with other well matured stepper motor driver, this motor is running silently. Please! advise.     

Other drivers may have properly tuned stepper driver and it is possible you haven't tune the DRV8711 settings to suit your stepper motor. What microstep mode was used by the other drivers? Can we get current waveform of the other drivers to compare with the current waveform of the DRV8711?

Please share the coil current waveform for further analysis. Without the current waveform we're unable to comment on this. The DRV8711 supports up to 256 microsteps mode, this mode will be the smoothest with lowest audible noise. TOFF must suit your motor for lowest audible noise. Please zoom in current waveform and share the tON and tOFF cycles for analysis. Thank you.

Regards, Murugavel 

1. I have resolved the issue of UVLO by installing 2 more 200uF 63V capacitors at power input of DRV8711 driver by time of your reply.

2. I have increased micro-steps to 256, of course noise is reduced but problem motor is not able to rotate smoothly above 250 RPM even after increasing the values of current around 4 Amps  in TORQUE register.

I should have shared current waveform of other drivers which have been tested with this available stepper motor but problem is access of  current waveform of the other drivers to compare with the current waveform of the DRV8711 is not available since there are conformal coatings to conceal the PCB against any probing. 

But not a issue, i will my level best to give current waveform. 

I was just tried to confirm that whatever i have observed in DRV8711 behavior is normal or abnormal after running the motor for few days. By now, most of problems i have solved myself. But somehow, i m not able to reduce the humming sound from motor at lower speeds upto 200 RPM.    

Please! advise me as per your experience, if any further improvement is possible.     





 

Hi Neeraj,

NEERAJ GUPTA said:

1. I have resolved the issue of UVLO by installing 2 more 200uF 63V capacitors at power input of DRV8711 driver by time of your reply.

This is good to know. I suspect your power supply is unable to provide the drive current hence it required additional 200 uF capacitors to avoid UVLO. This would also mean you'd still have a lot of voltage ripple but better than before to not cause UVLO. I'd recommend a higher current capacity power supply.

NEERAJ GUPTA said:

2. I have increased micro-steps to 256, of course noise is reduced but problem motor is not able to rotate smoothly above 250 RPM even after increasing the values of current around 4 Amps  in TORQUE register.

If you could share the current captures it would be helpful.

NEERAJ GUPTA said:

I should have shared current waveform of other drivers which have been tested with this available stepper motor but problem is access of  current waveform of the other drivers to compare with the current waveform of the DRV8711 is not available since there are conformal coatings to conceal the PCB against any probing. 

No PCB access is required for capturing current waveform. A low cost clamp-on current probe such as the https://www.hantek.com/products/detail/77 can be clamped to one of the stepper motor wires and its current waveform can be captured with an oscilloscope. 

NEERAJ GUPTA said:

By now, most of problems i have solved myself. But somehow, i m not able to reduce the humming sound from motor at lower speeds upto 200 RPM.    

Humming sound could be due to power supply ripple as well. Try with a higher capacity power supply. If the current waveform does not look to be a clean sinewave with 256 microsteps mode, the motor likely generates significant audible noise. I hope you'd be able to get a clamp-on current probe and look at the current waveform. At this point I do not have further inputs. Please close this thread as RESOLVED. Thank you.

Regards, Murugavel