Mitsubishi Electric MELSEC iQ-R I/O Module

This event code is registered in the event history if the attempt to disable the safety module function of the I/O module with diagnostic functions fails. This means 'Enable (1)' remains in Validation status area (Un\G5377) and the ALM LED does not flash (400ms cycle), preventing normal operation.

This error code indicates that a momentary power failure has occurred in the remote head module. If the transmission interval monitoring time for the master station or the I/O module with diagnostic functions is set too low, safety communications may stop as a result of such power fluctuations.

A value outside the permissible range of 6 to 3000 has been configured for the 'Transmission interval monitoring time' parameter. This incorrect setting prevents the module from operating correctly, as it relies on a valid monitoring interval.

A value outside the permissible range of 0 to 2 has been configured for the 'LED indication setting on error condition' parameter. This incorrect setting can lead to improper or missing LED indications when an error condition occurs.

A value outside the permissible range of 0 to 1 has been configured for the 'Wiring selection of input X' parameter, where 'X' denotes a specific input terminal. This incorrect setting impacts the wiring configuration of the designated input, potentially causing malfunction.

A value outside the permissible range of 0 to 4 has been configured for the 'Input response time X' parameter, where 'X' denotes a specific input terminal. This error can also occur if the 'Input response time X' is set shorter than the calculated input dark test pulse output time, which is derived from 'Input dark test pulse OFF time' and 'Number of pulse output for input dark test'.

A value outside the permissible range of 0 to 1 has been configured for the 'Double input discrepancy auto recovery setting' parameter. This incorrect setting affects how the system attempts to automatically recover from discrepancies detected in double input configurations.

A value outside the permissible range of 1 to 6000 has been configured for the 'Double input discrepancy detection time X' parameter, where 'X' denotes a specific input terminal. This incorrect setting impacts the timing and sensitivity of detecting discrepancies in double input configurations for the designated input.

A value outside the permissible range of 0 to 2 has been configured for the 'Input dark test pulse OFF time' parameter. This incorrect setting directly affects the duration of the OFF state during the input dark test, which is critical for accurate testing.

A value outside the permissible range of 0 to 2 has been configured for the 'Number of pulse output for input dark test' parameter. This incorrect setting impacts the count of test pulses generated during the input dark test, leading to potential test failures.

A value outside the permissible range of 0 to 1 has been configured for the 'Wiring selection of output Y' parameter, where 'Y' denotes a specific output terminal. This incorrect setting impacts the wiring configuration of the designated output, potentially causing malfunction.

A value outside the permissible range of 0 to 2 has been configured for the 'Output dark test pulse OFF time Y' parameter, where 'Y' denotes a specific output terminal. This incorrect setting directly affects the duration of the OFF state during the output dark test for the designated output, impacting test accuracy.

A value outside the permissible range of 0 to 2 has been configured for the 'Number of pulse output for output dark test' parameter. This incorrect setting impacts the count of test pulses generated during the output dark test, leading to potential test failures.

A discrepancy has been detected in a double input configuration, meaning the expected redundancy check has failed. This typically points to an issue with the physical wiring, the connected input devices, or an unused input terminal that has not been correctly configured.

During an input dark test, the module failed to detect the expected test pulses. This indicates a problem with the input dark test setup, the input wiring, the connected devices, or an unused input terminal that has not been correctly configured to be 'Not used'.

The duration for which the I/O system remained in a HOLD state exceeded its pre-set time limit. This typically occurs in safety-critical applications when there are issues with system switching or communication with Safety Integrity Level 2 (SIL2) Process CPUs.

An invalid value has been configured for 'Interrupt condition target setting [n]'. For an input module, the setting is outside the range of 0 to 3 and 7 to 10. For an output module, the setting is outside the range of 0 to 4 and 7. This prevents proper interrupt handling.

An invalid value has been configured for 'Interrupt condition target I/O terminal setting [n]'. The set value is outside the acceptable range of 0 to 16. This misconfiguration prevents the module from correctly associating an interrupt with a specific I/O terminal.

An invalid value has been configured for 'Input response time setting'. The set value is outside the acceptable hexadecimal range of 9H to DH. This incorrect setting can lead to improper detection of input signals or timing issues.

An invalid value has been configured for 'Input delay type setting'. The set value is outside the acceptable range of 0 to 2. This misconfiguration can cause incorrect timing for input signal processing.

An invalid value has been configured for 'Input delay time setting'. The set value is outside the acceptable range of 1 to 150000. This incorrect setting can result in improper input signal filtering or delayed responses.

An invalid value has been configured for 'Number of input ON times alarm detection count setting'. The set value is outside the acceptable range of 1 to 4294967295. This prevents the system from properly monitoring and alarming on input activation counts.

An invalid value has been configured for 'Event time stamp condition setting'. The set value is outside the acceptable range of 0 to 2. This misconfiguration can lead to incorrect or missing event timestamping.

An invalid value has been configured for 'Output delay type setting'. The set value is outside the acceptable range of 0 and 1. This incorrect setting can result in improper output signal timing.

An invalid value has been configured for 'Output delay time setting'. The set value is outside the acceptable range of 1 to 150000. This incorrect setting can lead to improper output signal filtering or delayed activations.

An invalid value has been configured for 'Number of output ON times alarm detection count setting'. The set value is outside the acceptable range of 1 to 4294967295. This prevents the system from properly monitoring and alarming on output activation counts.

This error indicates an output read-back malfunction, triggered by either an overload or an overheat condition within the output circuit of an I/O module with diagnostic functions. An overload occurs when current exceeds the rated value, typically due to a short-circuit in the output. An overheat condition arises from excessive internal module temperature, often a result of sustained overcurrent. Both scenarios pose a risk of ignition and burnout to the module's internal circuits.

During an output dark test, the expected test pulses were not detected. This signifies that the output circuit did not respond correctly to a diagnostic test, potentially due to wiring faults, issues with connected devices, or an internal hardware problem.

An internal hardware error was detected within the module. This can be caused by external electrical noise interfering with internal components or an actual failure of the module's hardware, compromising its functionality.

An error was detected on the external power supply connected to the I/O module. This could stem from issues with connected devices, wiring, incorrect voltage levels, or an improper power-on sequence relative to the module's own power supply.

A moderate error was detected in the counterpart device involved in mutual monitoring for safety functions. This indicates a problem within the inter-device safety communication or logic, which can compromise the overall safety integrity of the system.

This error occurs when the I/O module with diagnostic functions is started in normal mode, but its safety module function remains enabled. The module will not operate normally until the safety module function is successfully disabled, as indicated by 'Disable (0)' in Validation status area (Un\G5377).

An error related to safety parameters was detected during system startup. This usually points to an unsuccessful or corrupted write operation of the safety parameters to the module, which is critical for safety-related functions.

An error was detected in the configuration of the module. This may be due to incorrect physical mounting of the module or attempting to use an I/O module that does not support SIL2 mode within a safety-critical paired configuration.

A disconnection has been detected on an input terminal. This indicates a physical break in the wiring or loss of signal from the connected input device, preventing proper signal reception by the I/O module.

The number of output ON times has reached the pre-configured alarm detection count. This alarm indicates that a specific output has been activated a set number of times, potentially signaling that a connected actuator or contactor is nearing its operational lifespan or a process requires monitoring.

A disconnection has been detected on an output terminal. This indicates a physical break in the wiring or loss of continuity to the connected output device, preventing the module from controlling the device.

A short-circuit has been detected on an output terminal. This indicates an abnormally low resistance path, likely causing excessive current flow, which can damage the module or connected components if not addressed promptly.

An AC input signal fails to turn on, typically caused by step-like deformations in the input signal waveform around the zero-cross voltage. This issue often arises from power supply quality problems, such as those associated with off-line type Uninterruptible Power Supplies (UPSs).

Incorrect input data is received due to chattering when a device with a high input response speed is connected to a contact output module. The rapid, transient fluctuations from contact bounce are interpreted as multiple, unstable input signals, leading to erroneous data processing.

A leakage current from a contactless input switch prevents the input signal from reliably turning off. This occurs when the residual voltage across the input module terminals, caused by the leakage current, remains above the module's OFF voltage threshold, leading to an incorrect ON state.

A leakage current from a limit switch with an integrated neon lamp prevents the input signal from turning off. The characteristics of the neon lamp allow sufficient current to flow, keeping the input module's terminals above the OFF voltage threshold, which results in a false ON state.

A leakage current flows into the input module due to the inherent capacitance of long wiring cables, preventing the input signal from turning off. This is particularly common with twisted pair cables, which can have a line capacity of approximately 100pF/m, contributing to unwanted current flow.

A leakage current from a switch with an LED indicator causes the input signal to remain ON even when the switch is physically OFF. This occurs because the leakage current (e.g., 2.82mA at 24VDC for RX40C7) exceeds the input module's OFF current threshold (e.g., 2.0mA), preventing the input from reliably turning off.

An input signal does not turn off due to a sneak path current created by the use of two power supplies in the system. This unintended current flow bypasses the intended circuit, keeping the input module falsely activated, especially when voltage E1 is greater than E2.

The I/O status indicator LED for a specific input point is not illuminated, suggesting that the external input signal is either not present, not strong enough, or not being processed correctly by the I/O module. This can be due to a missing or incorrect external power supply to the I/O module or an internal module failure.

A load connected to a transistor output module operates solely when the external power supply is turned on, without the transistor output being actively commanded ON. This fault occurs because the external power supply is connected with reversed polarity, allowing current to flow via the output element's internal protection diode directly into the load.

When an inductive load is connected to a transistor output module, the load momentarily turns on while in the OFF state during system power-off. This is caused by a sneak current generated from the back EMF of the inductive load at the moment of shutoff, which can briefly re-energize the load.

When the external power supply is turned on, a load connected to a transistor output module momentarily turns on. This occurs due to stray capacitance (C) between the photocoupler's collector and emitter, allowing current (Ic) to flow into the transistor's gate, activating the output Y0 for a brief period (e.g., 100µs). This is more pronounced with high-sensitivity loads like solid-state relays or if the external power supply's voltage rise time is too fast (less than 10ms).

The RUN LED on the CPU module is not illuminated, indicating that the CPU module is not in an operational state or its 5V power supply is interrupted. This condition can be caused by insufficient power capacity, improper module mounting, or an internal CPU module failure, preventing system operation.

When one output of a transistor output (source type) module is turned on, other loads connected to different outputs simultaneously turn on. This fault arises from a non-connection or disconnection between the external power supply 0V and the common line of the load, allowing current to flow through parasitic circuits in the off-state output elements. Continuous operation under this condition can lead to module failure.

A load connected to a transistor output module fails to turn off, or may even turn on unexpectedly, when it operates with a minute current (0.1mA or lower). This behavior is attributed to the inherent leakage current present in the transistor output, which is sufficient to activate such low-current loads.

The triac output load fails to turn off due to a leakage current flowing through the triac module's built-in surge suppressor. This leakage current is significant enough to partially or fully energize the load, preventing it from deactivating completely when the output is commanded OFF.

The triac output fails to turn off when the load current is too low (below 25mA). In such conditions, the triac may not operate stably. If an inductive load is connected, the surge current during turn-off can keep the phototriac component in the triac active, preventing complete deactivation.

Excessive voltage is applied to the load when the triac output is in the OFF state. This happens because the load internally performs half-wave rectification, charging an internal capacitor (C). When the supply polarity changes, this charged voltage combined with the line voltage is applied across an internal diode (D1), potentially reaching approximately 2.2 times the supply voltage, risking D1 deterioration or fire.

The input module receives unintended input data, which is actually noise being interpreted as a valid signal. This can occur if the input response time is set too short, allowing transient noise pulses to activate the input, or if external electromagnetic interference affects the input lines.