KEYENCE GC-1000 Safety Controller Manual

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".