Why is there a mismatch in the analog voltage output measured by a multimeter and the one read by my drive?
This question is relevant to the following registers:
0x082 - Analog input 1 - Value for SPI drives
0x2082 - Analog input 1 - Value for EtherCAT/CANopen drives
Index | Sub Index | Name | Data Type | Access | Pdo Map. | NVM | Value range | Default value | Units |
|---|---|---|---|---|---|---|---|---|---|
0x2082 | 0x00 | Analog input 1 - Value | FLOAT | RO | Yes | No | Data type | - | - |
This parameter allows reading the value obtained from analog input 1, after being normalized and applying corresponding gain and offset.
The mismatch is caused by the value being normalized.
Example:
The analog voltage input = 0-3V.
Sensor outputting = 1.5V (multimeter reading)
Gain = 1
Offset = 0
Everest S XCR used, so input’s full-range is +/-10V.
Expected reading of the register = 0.5 V (normalized zero) + 1.5 V / 20 V (±10 V range) = 0.575 V.
Adjusting the gain to 20 and offset to 10 would make a 1:1 voltage relation between input and reading, meaning the value read and the actual volts inputted will be equal.
Additional information on the Analog Inputs: Inputs and outputs (novantamotion.com).