analogRead2()

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

uint16_t analogRead2(uint8_t ch)

Commands

Command	Arguments	Return Value	Operation
`analogRead2(ch)`	`uint8_t ch` — MPINO: analog pin such as `A0`; MPAINO: overall module channel number starting at `0`	`uint16_t`	Reads the corrected 4~20mA input value of the specified channel.

Example

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);
}

Precautions

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.

Built-in Commands in the Same Category

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ILOGICS Product Documentation

Table of Contents

analogRead2()

Commands

Example

Precautions

Built-in Commands in the Same Category