N5 Modbus RTU Online Manual

Analog inputs

The controller has 2 analog inputs with 10-bit resolution. They are located on pins 8 and 9 of X3. You can configure both analog inputs as a current input or as a voltage input with object 3221h.

You can read out the analog value in a NanoJ program and use it as you like, e. g., to specify the target speed.

Object entries

To read out and, if necessary, manipulate the value of the analog input, use the following OD settings:

  • 3220h (Analog Inputs):

    This object displays the instantaneous values of the analog inputs in ADC digits.

  • 3221h: (Analogue Inputs Control):

    With this object, you can switch the analog input from voltage measurement to current measurement.

  • 3320h (Read Analogue Input):

    This object displays the instantaneous values of the analog inputs in user-defined units.

  • 3321h (Analogue Input Offset):

    This is the offset that is added to the read analog value (3220h) before scaling (multiplier from object 3322h and divisor from object 3323h).

  • 3322h(Analogue Input Factor Numerator):

    This is the value by which the read analog value (3220h + 3321) is multiplied before it is written in object 3320h.

  • 3323h(Analogue Input Factor Denominator):

    This is the value by which the read analog value (3220h + 3321h) is divided before it is written in object 3320h.

Scale analog value

You read the value in object 3320h (Read Analogue Input): This object displays the instantaneous values of the analog inputs in user-defined units.

The user-defined units are made up of offset (3321h) and scaling value (3322h/ 3323h). If both are still set to the default values, the value in 3320h is specified in the ADC Digits unit.

Example

Analog input 1 has a measuring range of -10 V…+10 V. There is a voltage of 0 V…+10 V on the analog input, which, at a resolution of 10 bits, corresponds to the value range 512…1023 ADC digits.

To display the analog value in the physical unit of millivolt, proceed as follows:

  1. Write the value "-511" in 3321h:01h (Analogue Input Offset).
  2. Write the value "20000" (corresponds to the entire measurement range in millivolt) in 3322h:01h (Analogue Input Factor Numerator).
  3. Write the value "1024" (corresponds to the resolution) in 3323h:01h (Analogue Input Factor Denominator).

At the maximum voltage of 10 V, now read out the value "10000" in object 3320h (Read Analogue Input):

(1023 digits - 511 digits) * 20000 mV / 1024 = 10000 mV

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