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Writing to Digital Output but Analog Output is providing current instead

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SAS HWQ CONCEPT

Hello

I am performing a simple test as follows:

int dt = 200;
void setup() {
}
void loop() {
  digitalWrite(Q1_0, HIGH);
  delay(dt);
  digitalWrite(Q1_0, LOW);
  delay(dt);
}

The switch for all outputs is set to ON, meaning that digital outputs are enabled.
When running this program, I do see the led corresponding to Q1_0 blinking. But when plugging a resistor+LED on the actual Q1_0 output, nothing happens. Yet if I plug the resistor+LED to the A1_0, it does blink. Same behaviour is observed for Q1_1/A1_1 and Q1_2/A1_2.

Is anyone able to explain why that is?
Thanks in advance
Greg


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Joan Vilardaga Castro
Best Answer

Hi,

All the digital outputs (From QX.0 to QX.7) are opto-isolated outputs.

Therefore, you need to inject into the QVdc pin the voltage that you want in the outputs. In this way, the general voltage of the equipment is isolated from the voltage to which the inputs work.

It can work from 5Vdc to 24Vdc, in your case you want to connect 5Vdc to QVdc, and the GND to COM(-).

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