Author Topic: output control  (Read 12218 times)

nugrozt

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output control
« on: July 12, 2010, 09:23:53 PM »
i have a problem in using PLC, my project is control high voltage source to control temperatur furnace.
control temperatur using high voltage source. the problem is how to use special output of TM100D+1616(such as:PWM,PID control,ANALOG OUTPUT) that can handling this program.
i need to control temperatur at certain set point(SP), if temperatur less than SP then high voltage source must increase the voltage to increase temperatur furnace. otherwise, decrease the voltage to decrease temperatur.
nb: to control the high voltage source needs 0-12 V, that related to 0-2kV output of high voltage source.

regard
nugros

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Re:output control
« Reply #1 on: July 13, 2010, 12:14:38 AM »
It is possible to convert the 0-20mA analog output on the T100MD1616+ into 0-12V output if you connect the analog output to a 600 ohm resistor and ground. 20mA x 600 = 12V. So the output can be varied from 0V to 12V.

I am assuming that your high voltage output is electrically isolated from the PLC's low voltage circuit.
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nugrozt

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Re:output control
« Reply #2 on: July 13, 2010, 02:25:47 AM »
thanks.,

i need to  control 3 different high voltage source with the same output control, is it ok if i parallel 1 output PLC (0-12 V) to 3 different high voltage source?

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Re:output control
« Reply #3 on: July 13, 2010, 06:50:49 AM »
It depends on the impedance of the control input (0-12V) of your three loads. If these are high impedance inputs then it should be OK to connect the same output to all 3 of them in parallel.
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nugrozt

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Re:output control
« Reply #4 on: July 29, 2010, 05:16:22 AM »
i have problem with output DAC, i use the T-BASIC command SETDAC 1,2048 and connect a resistor (560 ohm) accross the output terminal D/A #1, when i measure the voltage between the resistor, it's just 4,7 V measured (in the manual book, it should have (560 ohm x 10mA= 5,6 V)?)
then, if i change output DAC with 4090,and the voltage measured is 4,9 V (why not 4,7 x 2 = 9,4 V)
was i wrong??

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Re:output control
« Reply #5 on: July 29, 2010, 09:24:06 AM »
Can you connect the DAC #1 output to a mA meter and check the output current when SETDAC 1,2048 and SETDAC 1,4090? What current did you get? You may have to calibrate the analog output current (there is a small preset next to the analog circuitry to calibrate the DAC).

Also you need to check if the analog voltage reference output 5V accurately? This is the voltage reference and if it is off then you need to turn the AVcc cal preset to get 5V.

If you can't get the 10mA or 20mA current after calibrating the AVcc reference the DAC preset then the DAC circuit may be damaged.
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