Configuring Power Outputs

Products documented with integrated power outputs: PDM32 and PDM08. MXm also has its own Power Outputs settings; the MXm/MXq manual explicitly limits that part to MXm. The output types, protection settings and diagnostic channels must be taken from the selected hardware.

Outputs on an added expansion are configured in that expansion’s panel. Some earlier MXS/MXG, MXS Strada, MXL2, EVO4S and EVO5 configurations expose auxiliary digital outputs through alarm actions. Their electrical ratings and available controls are different from the power-output settings described here.

Prepare Each PDM Load

Before opening Power Outputs, identify the connector/output, the load it supplies, its normal and starting current, the wiring protection requirements and the condition that should switch it off. Use the product’s output ratings and the load manufacturer’s requirements. The PDM product manuals require qualified installation personnel because these circuits can carry high current.

Give each output a functional name, such as CoolingFan. Keep the output name, its activation variable and its diagnostic channels easy to distinguish.

Choose the Output Waveform

PDM32 and PDM08 document these three modes:

  • Continuous: keep the output switched on while its activation logic permits. The connected load determines its current draw; the current limit is a protection setting.

  • PWM: switch the output repeatedly and vary its duty cycle. The duty cycle is the ON time divided by the total cycle time. A suitable load can use it for fan speed, pump speed or lamp brightness.

  • Square Wave: set the ON and OFF durations for a repeating pattern, such as a slow blinking output.

  1. Select the output and its working mode.

  2. For PWM, set the permitted frequency and the conditions or ranges that select each duty-cycle value. Set any transition time offered by the panel.

  3. For Square Wave, enter both the ON time and OFF time.

  4. Configure soft start and soft stop if needed and supported by that output.

The PDM32 manual describes 100 Hz PWM for its LMH outputs and a selectable 10-500 Hz range for its half-bridge/high-power outputs. The PDM08 manual describes 100 Hz PWM. These are product-specific settings; do not transfer a frequency range from one output type to another.

The PDM32 example of temperature-dependent PWM uses different duty cycles for different water-temperature ranges. Ensure the ranges cover the required operating conditions, then verify the value selected at every boundary. A transition time controls how the duty cycle moves between levels; it is separate from the PWM cycle frequency.

Set Activation and Deactivation Logic

PDM32 and PDM08 allow the same condition or distinct conditions for switching an output on and off. MXm documents its own per-output activation settings.

Choose either a direct channel comparison or a named status variable that contains the required logic. For a condition built from several inputs, specify whether All or Any must be valid. Set the qualification times offered by the selected output.

For example, a PDM fan can switch on above 100 deg C and switch off below 80 deg C. With distinct conditions, it remains on while the temperature is between those thresholds after activation. Using one threshold for both transitions produces different behaviour. These temperatures illustrate hysteresis; they are not recommended settings for every engine.

Soft start and soft stop control the output transition. The qualification time controls how long the input condition must be valid before the transition is requested. Configure these as separate decisions.

Set and Check PDM Protection

For PDM32 and PDM08, review the protection fields for every configured output:

PDM output-protection settings

Setting

Purpose

Maximum current

The sustained-current threshold for protection. Choose it within the ratings of the output, load, connectors and wiring.

Inrush allowance

Allows the starting transient for the configured period. The PDM32 manual describes short-circuit protection remaining active during this period.

Overcurrent latch-off time

How long excessive current is tolerated after the starting allowance before the output is disabled.

Retry delay and number of retries

Whether, when and how many times the output attempts to start again after an overcurrent shutdown.

Minimum current / open-load detection

The current below which the load is diagnosed as open. Set this for the actual load, rather than using the setting of an unrelated circuit.

Where the hardware offers open-load checking while the output is OFF, enabling it passes a small diagnostic current through the circuit. The PDM32 manual notes that this can be enough to illuminate some LED lamps. Check the behaviour of the connected load before enabling this option.

After the configured retries have been exhausted, the PDM manual describes re-enabling the output by taking the activation condition from ON to OFF and back to ON. Correct the underlying fault before requesting another activation.

Record and Display Output Diagnostics

PDM32 and PDM08 document a current channel and a status channel for each power output. MXm documents On/Off, current and status-related channels. Select the related channels and their logging options in the model’s panel.

Use these values in displays, alarms and CAN output just as you would other available channels. For example:

  • show fan current next to water temperature;

  • trigger a diagnostic alarm from the fan-output status;

  • log the activation request, actual current and status together so that a protection shutdown can be distinguished from a normal OFF request.

The PDM32 manual lists status values for normal operation, short circuit, open load, excessive temperature, overcurrent, undervoltage and overvoltage. Use the labels offered for the selected product; numeric codes and available diagnostics are not interchangeable between output families.

Verify Power-Output Behaviour

  1. Save and transmit the complete configuration to the correct device.

  2. In Live Measures, observe the source channels and the output’s current and status channels together.

  3. Verify the normal activation and deactivation conditions, including any delay, hysteresis and PWM transition.

  4. Check that the displayed messages and recorded values identify the intended circuit.

  5. Remove all forced channel values after testing and confirm normal readings.

Warning

Forcing a source value can activate a real power output. Use a suitable bench setup or isolate the actuators before testing the logic with forced values.

The complete sequence is illustrated in A Complete PDM32 Configuration Example.

Sources for Output Configuration