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Messages - roypthomas

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I was trying to read the NANO10 PLC DM[1]  data memory to cimplicty HMI using MODBUS/TCP protocol and RTU.

I defined protocol in cimplcity MBTCP0, created a device with device address 01,  and created a point with 41001 where I have setpoint value of type integer.

I created a GenerciPLC type and STAT_PLC type.  None of these methods worked.

I failed to read. What could be the problem?

Please advise for cimplicity HMI or iFIX or any other HMI with MODBUS/TCP or Modbus RTU.

Thank you

Technical support / Re:PIDdef, PIDcompute support
« on: March 01, 2013, 01:12:29 AM »
What I meant was that 25% duty cycle would return 47000 and 3% duty cycle would return 300. I am sorry, I will try your advise first and let you know.

Many thanks for your response. Making this PID work is very critical. I hope that you will continue to support until it is resolved.

I will try to send the program as attachment for your review.


Technical support / Re:PIDdef, PIDcompute support
« on: February 28, 2013, 01:01:12 AM »
encoder input to PLC


47000 for 3% PWM
300     for 25% PWM

setpoint 18%

I just need to control between 3 % to 25% as stated above.

I am almost unable to proceed further without PID working.
I am entirly depending on the your advise on how to choose the initial P and I values?

All numbers for p and I cant be FOUND trial and error. there must a proper procedure to calcualte THE INITITIAL setting, then we can adjust.

could you advise how to find p and i from the above ranages.

thank you


Technical support / Re:PIDdef, PIDcompute support
« on: February 25, 2013, 08:06:47 PM »
control input is 0 - 4096 (speed)
control output 0 to10000.
Control Input Setpoint 2048.

what is the P and I value that I can start with for the above control input and output range?.
There is no response if I follow the Nano10 software manual.

There is a demonstration in the user manual which defines  ONLY how to use PIDcompute fuction without explaining the important  P,I value calculation for PIDdef.  

The manual should have provided more importance on how to calculate P,I for PIDdef to define based on control input range an control output range.

Could you help calculating the initial value first, the PID tuning part ,I can guess based on trial and error.

Otherwise, I will have to write PID logic whcih will take sometime.

thank you

Technical support / PIDdef, PIDcompute support
« on: February 23, 2013, 02:27:00 AM »

I have tested on nano10 the following values on a 24V DC motor using a speed feedbacj series resister.
The series resitor measures  from 0 - 4095 (speed)
My PWM duty cycle control range must be from 500(5%) to 9500(95%) for frequency 15Hz.

what must be the PIDdef ?

what must be the PIDcompute command parameters?.

I need urgent help on PID configuration. please advise.


Technical support / Re:PID PWM
« on: February 06, 2013, 10:38:54 PM »
Thank you for your advise.

I had experimented with various nan010 supported frequency starting from 16.7Hz to 320kHz range.

I found that at 16.7Hz, it will support duty cycle 5% minimum speed to 60% for maximum speed.

Now I am trying to mesure the speed of the motor.
Either I need a tachometer or rotary encoder or a wheel with optical sensor.

Could please advise the model number of NPN optical sensor that can do the job for 100RPM at various duty cycle from 5% to 60% .

When the duty cycle is 5% the voltage across motor is around 7V where as when the duty cycle is 60^ it is around 23.45V.

Insted of optical sendor I tried to use a 50ohm resister to generate 5V that represents the speed. But using series resistor with motor generates 5V at full speed and 0V at minimum speed, it is not accurate and not linear.

Therefor I must use a NPN optical senor and wheel coupled to shaft of the motor.  

Can I use any LED as ligh source and the NPN sensor to detect the light through the wheel to generate pulses of 24V?

1. please advise the model numbers of LED and the NPN optical sensor.

I must get the speed count  for PID to generate the PWM.  
2. Please also advise the starting P,I values for the duty cycle range 500 to 6000 for the frequency 16.7Hz?

Technical support / Re:PID PWM
« on: February 01, 2013, 12:25:01 AM »
PIDDEF command set at 0 and 10000 . Always it stays at 10000

The SetPWM command has duty cycle and frequency. PID can be generated for Duty cycle, but how about the frequency?.

The maximum RPM value is 100, the encoder for rotation will generate 500pulses.

please advise

Thank you

Technical support / Re:PID PWM
« on: January 30, 2013, 04:45:07 PM »
I have used PID blocks in many PLC logic designers. But here when I apply the same principle, it does not work.

Could you please give some tips to make it work?.

Pulse count or frequency representing the motor speed is the input. I need to control speed output. What should be the P,I and D. My typical setpoints will be 50RPM,25RPM,75RPM 100RPM.

The maximum RPM of motor is 100RPM.

The interesting thing is the PID compute function does not produce any value when there is a change. Currently the P is 20000, I=20, D=0

please help
Thank you

Technical support / Re:PID PWM
« on: January 29, 2013, 04:54:39 PM »
The PWM and motor workss fine without PIDcompute function.

The PIDcompute function does not work.
what should be the P ,I, D value for a motor with RPM of 100.
The encoder will give 500 pulses for one revolution.

With the sample SetPWM program the motor responds for different frequency. In the documentation, there is a demonstration of PID and PWM for DC motor speed control . But The frequency parameter is missing in the SetPWM function.

please advise what values should I use to control the motor in the entire frequecy range supported by the Nano10.

My requirement is to control 100rpm motor with PID closed loop and PWM.

Thank you.

Technical support / Re:PID PWM
« on: January 23, 2013, 01:29:47 AM »
I found the 24V encoder with 500pulses to count the speed of the motor. One rotaion is 500 pulses. I am not sure whether the nano can detect 500pulses for each rotation. The motor is 100RPM motor consuming 130mA and encoder consuming 80mA.

The power supply to PLC is 24V, 2.2Amp rating.

Do you see any issue if I used PWM to drive motor using PID control with anoove specs and encoder of 500pulse/revolution?

Technical support / Re:PID PWM
« on: January 22, 2013, 12:50:47 AM »
if I used SETPWM 1, 5000,1000 as advised, how can I troubleshoot whether the statement is working ?
Will I get a 24V pulse or can I measure a frequency.

If I simply connect the power supply accross the output 3,4 ,will the motor respond?

what are the necessry changes that needed to combine SETPWM program and PID program provided in the sample?

Technical support / Re:PID PWM
« on: January 22, 2013, 12:39:12 AM »
what would be the voltage (amplitude) level of PWM pulses when we connect 24V, 1A DC power source?. Could you please advise the 24V motor current rating for a stable PID based PWM control ?.

which solution is less complicated ,Tachometer or encoder?

please advise

General Discussions / Industrial type high performance PLC
« on: January 20, 2013, 09:57:37 PM »
please advise an Industrial type high performance PLC with support 150 digital inputs and few AI.

Technical support / PID PWM
« on: January 20, 2013, 07:08:23 PM »
Could any one advise the programming steps to configure the first channel  3,4 output pins for the PWM from the putput od PID for the control of 100rpm 24VDC, 190mA motor?. Assume the setpoint is 50rpm.
Please also advise the connections and the voltage/current required for the outputs.

I have tried the SetPWM and PID sample programs. But it does not work. I may need to change the values of frequency.

please advise.

Thank you.

The figure 8.1 shows a simple 24V signal NPN type optical sensor that can be connected to the PLC to measure the RPM.

Could you advise the model or part number that I can purchase?


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