The sensor is operating normally, but the K3NR Digital Panel Indicator's display is not changing. Wh

The following three causes are most likely.

Cause 1. The sensor is wired incorrectly.

  • When using a 3-wire sensor, connect to terminal 10 (power supply +), terminal 11 (power supply −), and terminal 1 (output).
  • When using a 2-wire sensor (NPN open-collector output), connect to terminal 11 (power supply −) and terminal 1 (output).
  • When using a relay contact or Solid-state Relay (NPN open-collector output), connect to terminal 11 (power supply −) and terminal 1 (output).
  • When using a sensor's voltage pulse output or a Mitsubishi inverter's FM output terminal, connect to terminal 3 (+ side) and terminal 11 (power supply −).

Note:The FM output from a Mitsubishi inverter is a voltage pulse output.

NB: NPN input or voltage pulse input connections PB: PNP input connection
NPN open-collector output
or NPN DC 2-wire output
Contact output Voltage output PNP open-collector output

When using an NPN DC
2-wire sensor, input +V to
terminal 1 and -V to
terminal 11.

When shorted, about 12
V and 13 mA (nominal)
will flow.

With using a voltage pulse
input that is not from a 3-wire
sensor, input +V to terminal 3
and -V to terminal 11.

Cause 2: The sensor's capacity does not match the K3NR.

Check the sensor's leakage current. When connecting to a K3NR, select a sensor with an OFF leakage current of 1.5 mA max.
It is especially important to have an appropriate leakage current when using a 2-wire sensor or Solid-state Relay.

Cause 3: The auto-zero time setting is too short.

The K3NR calculates the predicted pulse interval in order to predict when the next pulse will be input. If a pulse input is not received within a certain time, it is necessary to indicate that rotation has stopped (set display value to 0), and the auto-zero time specifies how long the K3NR will wait before determining that rotation has stopped. If this auto-zero time is set to a value shorter than the pulse interval, the display is forcibly set to zero. 

First, restore the auto-zero time to its default setting (X = 9.9999, and Y = 10 E 9).

If it is verified that measurements can be taken, set the auto-zero time to a value appropriate for your application.

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