analogRead2()

analogRead2() reads the corrected 4~20mA input value of the specified channel.

uint16_t analogRead2(uint8_t ch)

Connect an X input module to MPAINO-8A8R(T) and select Analog Input Module → X. Set CH0 DIP switches 20mA and GND to ON, then connect the 4–20mA signal.

void setup() {
  Serial.begin(115200);
}
 
void loop() {
  const uint16_t value = analogRead2(0);  // Read the corrected 4–20mA value from CH0.
  if (value == ANALOG_READ2_ERROR) {
    Serial.println(F("4-20mA input error"));
  } else {
    Serial.println(value);
  }
  delay(500);
}

• Set the MPAINO X module CH0 DIP switches 20mA and GND to ON, and wire the current input with the correct polarity.
• An input of approximately 3.6~4.0mA returns the normal value 0; inputs below 3.6mA return an error value.
• Error values help detect open circuits. The user must implement final alarms and safety actions in the program.
• IanalogRead2() and IanalogRead2f() also return 65535 on error, rather than a user-range value. Check for errors before using the result.
• The full int32_t range is available for min~max in IanalogRead2(), but if the normal range includes 65535, it cannot be distinguished from an error value.
• analogRead2Avgf() uses state and a buffer separate from analogRead2Avg(). Using both increases SRAM usage.
• If samples is 0 or memory allocation fails in analogRead2Avgf(), it returns the current valid corrected value as a float.
• On MPINO, do not use analogRead2() on voltage/NTC channels that are not 4~20mA inputs.
• For MPINO products requiring analogReference(EXTERNAL), set it first in setup().
• IanalogWrite2() and IanalogWrite2f() are convenience outputs dedicated to 4~20mA. Avoid alternating them with IanalogWrite() on the same channel.
• The analog output circuit requires an external 12~24V supply. USB power alone may not provide normal output.
• Verify actual current input/output with measuring instruments after preparing a test product.

• analogRead2Avg() View detailed description
• analogRead2Avgf() View detailed description

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