KEYENCE GC-1000 Safety Controller Manual

Confirm that there are no new risks introduced (such as the bypass function not being misused).

6.4 Equipment replacement steps

When GC-1000 or GC-1000R is damaged and needs to be replaced, strictly follow the following sequence:

Power outage: Cut off the power supply to the GC series and all peripheral devices (especially relay output loads).

Disassembly: Unplug all connecting cables, remove the expansion units on both sides, and remove the faulty unit from the DIN rail.

Reserve system memory: Remove the "System Memory" card from the slot on the left side of the faulty unit, which stores project programs and configurations. It must be installed in the same position as the new unit.

Install new unit: Reinstall the new unit in the original order, connect the expansion unit and cable.

Power on and clear CRC error: After power on, the main controller LCD will display "Activation CRC Error". Follow the on-screen prompts (usually requiring revalidation of the configuration), and then power off again.

Functional verification: Conduct a complete security function test to confirm that there are no abnormalities.

When replacing expansion units or remote I/O modules, there is no need to move the system memory card, just ensure that the module model and sequence are exactly the same as the original configuration.

Common fault cases and solutions

Case 1: Safety output cannot be connected, ERROR LED flashes

Possible reasons: Reset logic error, or EDM feedback not met.

Diagnosis: Connect to GC Configurator and check the status of the function block. If the "Reset" function block displays "Waiting for Reset Input", check the wiring of the reset button and whether it is configured as a pulse input.

Solution: Confirm that the reset button is an instantaneous NO contact and that the pulse width is sufficient (usually>200 ms). If EDM is used, check if the NC feedback loop of the contactor is closed.

Case 2: Dual channel safety input difference fault

Phenomenon: After pressing and releasing the emergency stop button, the safety output does not recover, and the controller reports a "Discrepancy error".

Reason: The asynchronous time between the two NC contacts during release exceeds the set difference time (usually 500 ms by default).

Solution: Check the mechanical synchronization of the emergency stop button, or increase the difference time parameter appropriately (but not exceeding 3 seconds, otherwise it does not meet the requirements of EN 574 for manual operation).

Case Three: GC Link Slave Communication Interruption

Phenomenon: LINK LED turns off or flashes red light (if any), and safety output is turned off.

Reason: Cable breakage, incorrect terminal resistance setting, loss of power supply from the substation.

Solution: Check the GC Link dedicated cable (recommended by Keyence) and confirm that terminal resistors (ON position) have been set at both ends of the bus. Scan the network using GC Configurator.

Case 4: Early End of Relay Output Contact Life

Reason: Improper use of surge suppressors. Although the relay model GC-1000R has a built-in protective diode, for inductive loads (contactor coils), RC suppressors or varistors still need to be connected in parallel at both ends of the load.

Solution: Install surge absorbers of appropriate specifications on each inductive load. Avoid capacitive absorbers (which may cause false triggering). According to the electrical life curve in the reference manual, if the load current is high, it should be downgraded for use (e.g. maximum 5A below 40 ℃).

Software and documentation support

Programming software: GC Configurator (free download), supports functional block programming, online monitoring, and error log export.

Related manuals:

GC Series User Manual: System Configuration, Startup Steps, Software Operation.

GC Series Function Block Reference Manual: Input/output definitions and timing diagrams for all available function blocks.

Compliance certification: CE, UKCA, UL, cUL, CCC, T Ü V S Ü D certification, compliant with IEC 61508, EN 62061, ISO 13849-1.