KEYENCE GC-1000 Safety Controller Manual

KEYENCE GC-1000/GC-1000R Safety Controller Engineering Configuration and Troubleshooting Manual

In the field of industrial automation, programmable safety controllers are gradually replacing traditional hard wired safety relays to meet increasingly complex mechanical safety requirements. The Keyence GC series safety controllers have become the preferred solution for many equipment manufacturers and system integrators due to their modular expansion capabilities, rich communication interfaces, and safety levels up to SIL 3/PL e/Cat. 4. Among them, GC-1000 is a semiconductor output type main controller, while GC-1000R has three sets of built-in relay outputs, suitable for directly driving AC loads. This article will provide a comprehensive and actionable practical guide for engineering and technical personnel from the dimensions of system selection, installation and wiring, functional block application, response time calculation, fault classification, and equipment replacement.

Comparison of Product Positioning and Core Specifications

The GC-1000 and GC-1000R constitute the two main controllers of the GC series, with the main differences reflected in output types and I/O points.

Project GC-1000 GC-1000R

Safe input points 16 14

Safe output (semiconductor) 6-way PNP -

Safety relay output -1 set (3a contacts)

AUX output 4 channels (PNP/NPN optional) 4 channels

Test output 4 channels and 10 channels

GC Link ports 2 x 2

Communication interface USB+Ethernet USB only

Network protocols such as EtherNet/IP, PROFINET, Modbus/TCP, etc. are not available

Dimensions (W × D × H) 60 × 95 × 90 mm 85 × 95 × 90 mm

Both support up to 10 expansion units and 4 remote I/O modules, and are connected to slave devices such as safety light curtains and safety door switches through GC Link. The GC-1000R is larger in size due to its built-in relay and does not have Ethernet communication capabilities, making it suitable for traditional applications that do not require fieldbus integration.

Safety parameters (applicable to both)

T1 (validation testing interval): 20 years

Hardware fault tolerance: 1

Safety status: Safety output OFF

PFH (dual channel semiconductor output with self diagnosis): 1.02 × 10 ⁻⁹/h

PL：e（Cat.4）

This means that the GC series can operate stably for a long time at the highest level of safety integrity, suitable for high-risk equipment such as stamping machinery, robot workstations, packaging lines, etc.

Installation environment and mechanical installation requirements

2.1 Environmental Restrictions

Do not use GC series in the following places:

Direct sunlight, ambient temperature exceeding -10 ℃~+55 ℃, or humidity exceeding 5%~85% RH

Presence of corrosive gases, flammable gases, salts, iron powder, or oil mist

Direct vibration or impact (must meet the vibration frequency of 5-9 Hz with a half amplitude of 3.5 mm and an acceleration of 10 m/s ² between 9-150 Hz)

Altitude exceeding 2000 meters, strong magnetic field or radiation area

2.2 Installation Method

The controller must be installed in a control cabinet with a protection level of IP54 or higher. Install using a 35mm wide DIN rail as follows:

Hang the upper hook on the back of the device onto the upper edge of the guide rail;

Press the lower part until the lower hook locks in place;

Confirm that all hooks are engaged.

Functional grounding of DIN rails.

2.3 Heat dissipation distance

When installing a single unit, maintain a minimum heat dissipation gap of 30mm in all directions.

When using a bus expansion unit, there should be a minimum distance of 60mm between the upper and lower units.

If the temperature inside the cabinet exceeds the standard, forced air cooling or increasing the gap should be used.

2.4 Expansion Unit Connection

The right side of GC-1000 can connect up to 10 expansion units (such as GC-S1R, GC-A16, GC-B30, GC-R45, etc.). GC-1000R only allows connection to GC-S1R or GC-B30 and cannot use bus expansion units. During installation, remove the protective cover of the right interface, insert the locking rod of the right unit into the slot of the left unit, and then lock the upper and lower locking rods.

Electrical wiring specifications and safety precautions

3.1 Power Supply and Grounding

Power supply voltage: 24 V DC, GC-1000 allows -30%~+20%, GC-1000R allows -20%~+20%, both require Class 2 power supply.

Power consumption: maximum 200 mA.

Functional grounding: The 0V terminal of the power supply must be connected to the system grounding point, and the DIN rail must be grounded.

3.2 Safe input wiring

Safe input compatible with dry contacts (mechanical switches) or PNP output sensors. Do not use NPN output devices. Electrical parameters:

ON level: ≥ 11 V/2 mA

OFF level: ≤ 5 V/1.5 mA

Maximum cable length: 100 meters

When SIL 2/PL d and above levels are required and PNP output sensors are used, equipment with dual OSSD outputs and inter channel short circuit detection function (such as Type 4 safety light curtains) must be selected.

Application of test output: The GC series provides multiple test outputs (PNP, maximum 100 mA), which can provide pulse power for external NC contact sensors to detect cross circuits and short circuits. Typical wiring example:

Test output T0 → emergency stop button NC contact → safety input I0

Test output T1 → second set of NC contacts of the same emergency stop button → safety input I1

Comparing the timing of two pulse signals within the device, if an unexpected level occurs, it is determined to be a crossover circuit fault.

3.3 Safety output wiring

Semiconductor output (GC-1000):

PNP type, maximum load current 500 mA/point

Residual voltage ≤ 2.0 V

Maximum capacitive load of 0.5 μ F

Maximum cable length of 30 meters

Built in overcurrent protection and reverse connection protection

Important safety warning: The load must be connected between the safety output and 0V. If mistakenly connected to+24V, the load will still be powered when the safety output is OFF, causing an extremely dangerous reverse logic state. In addition, to achieve SIL 3 level single channel safe output, protective measures must be taken to prevent short circuits between the output terminal and the power supply (such as laying cables inside the control cabinet or using armored pipes).

Relay output (GC-1000R):

3 sets of normally open contacts (3a)

Rated load: 250 VAC/6A (resistive), 30 VDC/6A; 240 VAC/2A（AC-15），24 VDC/1A（DC-13）

Mechanical lifespan: 100000 cycles (rated load) to 500000 cycles (light load)

Minimum OFF time: 300 ms (relay output recovery delay)

Each contact needs to be connected in series with a 10A fast melting fuse (IEC 60217) to meet the requirements of IEC 61131-2.

3.4 AUX output

Four auxiliary outputs are non safety signals that can be used to indicate status. It can be configured as PNP (100 mA) or NPN (20 mA) output through external wiring. For example, connecting indicator lights or PLC digital input modules.

Function Block Application and Security Logic Design

The GC series uses GC Configurator software for logic programming and adopts Function Block graphical language. Here are the key usage points for several key functional blocks.

4.1 Reset Function Block

Meets the requirements of ISO 13849-1:2015, clause 5.2.2. Used to manually restore safe output after safety conditions are met.

Key configuration:

Reset input settings: It is recommended to choose "Pulse input" instead of "Edge input". Due to the susceptibility of edge inputs to noise pulse interference, unexpected resets may occur. If the risk analysis does allow the use of edge input, it must be accompanied by the "reset enable input" function.

Reset switch: It must be a manually operated device (button or key switch), installed outside the hazardous area, and the operator must be able to clearly observe that there is no one in the area.

Interlock status indication: According to local regulations, it may be necessary to install indicators (such as indicator lights) to display the interlock status.

4.2 Dual Reset

Suitable for scenarios where multiple operators enter hazardous areas. Two people need to operate two reset buttons separately:

The operator who leaves the danger zone at the end operates reset 1.

External observers or another operator operate reset 2.

The reset button 2 should be installed in a position where the entire danger zone can be observed.

Prohibited use scenario: If someone may enter a dangerous area after resetting 1 and before resetting 2, this function block should not be used.

4.3 Existence Detection Reset

The reset enable signal comes from the safety laser scanner or safety light curtain. Reset is only allowed when the detection device confirms that there is no one in the danger zone. Suitable for large automated warehouses or robotic work units.

4.4 Mode Changing Control

Used to select manual/automatic operation modes. Different combinations of input terminals IN1~IN3 correspond to four modes of output. If you are concerned about accidental mode switching due to cable breakage, you should set Mode 4- in this mode, when any input is disconnected, the mode output is forced to "no valid mode" and can be programmed to turn off all safety outputs.

4.5 Manual Mode Control (MMC)

Used to temporarily pause security functions (such as light curtains) during setup, teaching, or maintenance. It is necessary to strictly comply with the requirements of IEC 60204-1 "Safety Function Suspension" and ISO 10218-1 regarding robot operation modes.

Mandatory measures:

Prohibit pausing emergency stop function: Even in manual mode, all emergency stop buttons must remain valid.

Using enabling devices: Dangerous movements in manual mode can only be triggered by "hold run" devices (such as three position enabling switches, momentary buttons, or dual hand control boxes).

Mode selection switch: It is strongly recommended to use a key equipped authorization switch to select manual mode.

Status indication: It is necessary to clearly indicate that the current mode is manual (such as rotating warning lights or HMI display).

Avoid multiple manual controls: The same machine should not have multiple manual mode controls; If unavoidable, interlocking logic should be designed to prevent conflicts.

4.6 Unlock Control

Used to control the locking device of protective doors (such as electromagnetic locks). Used in conjunction with the unlocking output of the safety door switch, it supports two types: "Power to release" and "Power to lock".

Unlock enabling conditions (all must be met):

The speed of dangerous moving parts has been reduced to a sufficiently low-risk level;

Or the driving torque has dropped sufficiently low;

Or if the driver has been turned off, the delay parameter should consider individual differences and aging of the machine.

4.7 Bypass

This function block is used to temporarily pause security functions (not for regular blocking). When using a bypass, a safety level signal must be used as the bypass input (such as a confirmation signal from a safety PLC or output through a manual mode control block). Using only non safety signals to trigger the bypass will lower the overall safety level of the machine to the level of that signal.

Time limit: The duration of the bypass should be as short as possible. If it takes more than 1 hour, the "bypass enable" function or safety device signal (such as light curtain obstruction confirmation) must be used.

Important warning: The bypass function block is not used for masking. When materials automatically pass through the light curtain, a dedicated Muting function block should be used.

Response time calculation and safety distance verification

When calculating the safe distance (such as the minimum distance from the light curtain to the hazard source), the total response time of the entire system from sensor triggering to actuator stopping must be considered. The response time of GC series is calculated according to the following formula:

5.1 Basic Formula

Ttotal

=Tfoundation

+TEnter additional

+TOutput additional

+T Function block attachment

T total=T foundation

+T Enter additional

+T Output additional

+T Function block attachment

5.2 Parameter Values

Basic response time: 4.8 ms (from input signal change to logic processing completion)

Input OFF → ON or ON → OFF: both are 4.8 ms

Additional time (input side):

Input on the main controller (GC Link or terminal block):+0 ms

Input on expansion unit or remote I/O module:+1.7 ms

Input filtering time: For example, if the filtering is set to 0.5 ms, then+0.7 ms+filtering time (i.e. 0.5 ms)=+1.2 ms

Additional time (output side):

Safety output on the main controller (semiconductor):+0 ms

Safe output on expansion unit:+2.4 ms

GC-1000R relay output:+10 ms

Function block attachment:

Use the OFF delay or ON delay function block: add the set delay time.

Connect registers (Store/Load) in series: add 2 ms to each pair of registers.

5.3 Calculation Example

Assuming system configuration:

The emergency stop button is connected through the main controller's safe input I0 (without filtering).

The program uses an ON delay timer (set to 50 ms) and a register pair.

The safety output drives the contactor from the semiconductor output of the main controller.

T total=four point eight(Basic)+0(Input additional)+0(Additional output)+fifty(ON Delay)+two(Register)=fifty-six point eight ms T total=4.8 (Basic)+0 (Input Additional)+0 (Output Additional)+50 (ON Delay)+2 (Register)=56.8 ms

According to ISO 13855, safe distance S=K×(T total+T braking)+C S=K×(T total+T braking)+C， take K=one thousand and six hundred mm/s K=1600 mm/s， The pre braking distance contributed by the controller alone is 1600 × 0.0568 ≈ 91 mm.

Fault diagnosis and maintenance

6.1 LED Status Indication

Meaning of LED status

POWER green light, normal power supply

Turn off no power supply

ERROR red flashing error occurred (specific error code needs to be checked)

Extinguish without error

LINK (GC-1000 only) green light GC Link established

Green flashing data transmission in progress

Extinguish no connection

When the ERROR LED flashes, it is necessary to connect to the GC Configurator to read detailed diagnostic information. The LCD screen of the controller (on the main controller) will display an error code, such as "Activation CRC Error" indicating that the configuration check has failed and the program needs to be downloaded again.

6.2 Misclassification

Category affects program behavior

Minor abnormal information does not affect the continued operation of security functions

Warning may affect normal operation, but continues to operate safely

Error: Unable to execute relevant security functions properly, related output block OFF continues to run but restricted

Serious error: The controller itself has malfunctioned, and all safety output OFF programs have stopped

6.3 Periodic Inspection

After initial debugging: Check the installation, wiring, and functionality according to the requirements of this manual.

Regular inspection: at least once a year. If local regulations or risk assessments require shorter cycles, comply.

Situations triggering inspection: replacement of equipment, modification of programs or wiring, long-term shutdown, or occurrence of accidents.

The inspection content should include:

Trigger each safety input (emergency stop, light curtain obstruction, door opening, etc.), confirm that the safety output is correctly closed and the actuator stops.

When the safety output self diagnosis is disabled, the measured output voltage after manually triggering the emergency stop should be<5V.

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.