Measurement Underflow

What does 263 mean?

This error indicates that the measured signal value on an analog input channel is below the minimum range or threshold the I/O module expects. Possible causes include a disconnected sensor, a sensor providing too low a signal, or a problem with the sensor's power supply, resulting in no meaningful input.

• The analog sensor is disconnected, or an open circuit exists in the wiring between the sensor and the I/O module.
• The sensor itself has failed and is not outputting any signal or is stuck at its minimum output value (e.g., 0mA, 0V).
• Incorrect scaling parameter (e.g., P3-00 'Min Analog Input Value') configured in the I/O module's settings.
• Loss of power supply to the analog sensor, preventing it from generating an output signal.

Click steps to track your progress.

1. 1

   1. Verify that the analog sensor's power supply (e.g., 24VDC) is present and within specified limits.

2. 2

   2. Measure the actual analog signal (e.g., current or voltage) at the sensor's output terminals.

3. 3

   3. Using a multimeter, check the continuity of the wiring from the sensor to the analog input terminals on the I/O module.

4. 4

   4. Verify that the configured input range parameter (e.g., P3-00 or scaling limits) in the I/O module matches the sensor's output range.

5. 5

   5. Temporarily connect a known good signal source (e.g., 4-20mA generator) to the analog input to test the module.