Q: What does the flashing red FAULT indicator mean on the IFM AC2566 module with combined pressure and level sensors on AL-1 and AL-2?

The flashing red FAULT indicator on the IFM AC2566 module indicates a device fault related to the sensors connected to the AL-1 and AL-2 inputs, particularly when it comes to combined pressure and level sensors. Possible causes of the flashing red FAULT indicator: Analog signal out of measurement range on an activated input. No sensor connected to an activated input. Broken cable or incorrect wiring. Particularities with combined sensors (pressure + level): These sensors have an analog output on pin 2 and a 24 V output on pin 4. It is essential to configure the module correctly to avoid triggering FAULT errors: Ensure that the switching output cannot switch. To do this, configure an unreachable switching point or select the NPN switching mode. Checks to perform: Check the configuration of the combined sensors according to the recommendations above. Verify the proper connection of the cables, especially to pins 2 and 4. Measure that the analog signals are within the expected range. Confirm that the AL-1 and AL-2 channels are properly activated in the module settings. By following these points, you should be able to identify and correct the cause of the flashing red FAULT indicator on your IFM AC2566 module.

Question 1

How to resolve the alarm of the IFM AC2566 module (slave 29) on the AS-i controller despite normal level and pressure values on the HMI?

Accepted Answer

When the IFM AC2566 module displays an alarm on the AS-i controller while the level and pressure data are correctly transmitted to the HMI, it generally indicates a peripheral fault or a configuration issue with the module's parameters. The fact that the analog values are passing correctly suggests that the AS-i communication is functioning, but the module detects an anomaly on the analog inputs.

First, check the LEDs of the AC2566 module: If the red FAULT LED flashes, it indicates a peripheral fault. This occurs when at least one analog signal is outside the measurement range (< 1 mA or > 23 mA), when a sensor is not connected to an activated channel, or when a wire break is detected. Check pin 2 (AI+ analog input) and pin 4 (AI- analog input 0 V) on the M12 connector to verify the connections of the level and pressure sensors. If the yellow LED corresponding to the channel also flashes, it confirms this issue.

Check the channel configuration: The P1 and P2 parameter bits of the module control the activation of the 4 analog channels. If the active channel settings do not match the connected sensors (for example, a channel is configured as active while no sensor is connected), the module reports a peripheral fault. Access the AS-i module configuration on the controller to adjust the settings: P1=0, P2=1 activates the first 2 channels, P1=1, P2=0 activates 3. Disable unused channels.

Check the connections: For the AC2566, which measures 4-20 mA currents, ensure that the internal shunt (parameter bit P0) is correctly activated for a 2 or 3-wire sensor, or deactivated for a 4-wire sensor. The M12 cables between the sensors and the module pins must be in good condition. A wire break generates a value of 32767 (0x7FFF) with the yellow LED flashing, triggering the alarm.

Check the transmission delays: The analog conversion time varies depending on the number of active channels: 20 ms for 1 channel, 120 ms for 2 channels, 180 ms for 3 channels, or 240 ms for 4 channels. If the AS-i controller expects the data faster than the module can provide them (especially with 3 or 4 channels), an alarm may be generated. Ensure that the controller's scan cycle is compatible with the total transmission time (conversion + AS-i transmission).

Check the power supply: The green PWR LED should be continuously lit to indicate a present AS-i voltage. If external 24 V power is used (AUX LED lit), check that the module is mounted on an FK-E base (AC5003 or AC5011). Insufficient or unstable voltage can generate sporadic errors.

By identifying which of the LEDs is flashing, you will pinpoint the exact cause: flashing yellow LED = analog input problem, flashing red LED = peripheral or configuration fault. A reset of the module and revalidation of the slave addresses (29 in your case) via the AS-i configurator may also resolve persistent anomalies.

Question 2

Does the IFM AC2566 module have a built-in NPN switching button?

Accepted Answer

The IFM AC2566 module does not have a dedicated physical button or switch for NPN switching directly on the module itself.

The configuration of the NPN switching mode must be done on the combined sensor connected to the module, and not on the AC2566 module. Here are the key points to remember:

NPN switching is a function to be set at the level of the combined sensor (for example, a pressure or level sensor) used with the module.
To prevent the switching output from activating, you can:

Set a switching point out of range on the sensor.
Configure the sensor to use NPN switching according to its own settings.

The exact method of configuration depends on the model and manufacturer of the sensor, which may include buttons, adjustment screws, or electronic menus on the sensor itself.

The AC2566 module simply monitors the signals from properly configured sensors. It has internal settings (bits P0, P1, P2) for other adjustments, but NPN switching is exclusively configured at the sensor level.

Question 3

What does the flashing red FAULT indicator mean on the IFM AC2566 module with combined pressure and level sensors on AL-1 and AL-2?

Accepted Answer

The flashing red FAULT indicator on the IFM AC2566 module indicates a device fault related to the sensors connected to the AL-1 and AL-2 inputs, particularly when it comes to combined pressure and level sensors.

Possible causes of the flashing red FAULT indicator:

Analog signal out of measurement range on an activated input.
No sensor connected to an activated input.
Broken cable or incorrect wiring.

Particularities with combined sensors (pressure + level):

These sensors have an analog output on pin 2 and a 24 V output on pin 4. It is essential to configure the module correctly to avoid triggering FAULT errors:

Ensure that the switching output cannot switch. To do this, configure an unreachable switching point or select the NPN switching mode.

Checks to perform:

Check the configuration of the combined sensors according to the recommendations above.
Verify the proper connection of the cables, especially to pins 2 and 4.
Measure that the analog signals are within the expected range.
Confirm that the AL-1 and AL-2 channels are properly activated in the module settings.

By following these points, you should be able to identify and correct the cause of the flashing red FAULT indicator on your IFM AC2566 module.

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