MICRONOR AG
MR340-1 DIN Rail Module Controller
Page 23 of 74
3.6
Power-up or Periodic Optical Sensitivity Calibration
As part of the normal power-up procedure, it is possible to perform an optical power
calibration. This is useful so that the system immediately starts counting with the highest
accuracy. The external HOMING Input (J1-Pin 3) of the controller is configured in such a way
that when a +24V signal is applied to this input, the internal counter is Reset to the Preset
value stored in Register 0x209. If so configured as described herein, the input amplifier level
calibration may be initiated at the same time.
Optical sensistivity calibration for linear sensors
At power up, it is recommended to move the MR343 sensor head to a clear area of the film
strip and then initiate a +24V logic pulse of ~100ms to 1sec duration to the HOMING Input
input (J1-Pin 3).
Instead of a +24V logic pulse on J1-15, the sequence may be initiated using Modbus FC05
0x007.
Register 0x208 must be configured to 0x03 in order for the above procedure to work properly.
This procedure can also be repeated at periodic interval or during self-test cycles.
Optical sensititivty calibration for rotary sensors
For MR34X series rotary sensors, optical sensitivity calibration is performed in real-time when
the encoder is rotating. The controller monitors the signal lows and highs and sets the
internal gain accordingly. Therefore, no special calibration procedure is required for rotary
sensor.