Skip navigation

E-STOP (9-pin 'D' plug)

The E-STOP connector is provided to allow connection of an external EMERGENCY STOP switch into the SPA3. The machine manufacturer or product installer must perform a risk assessment to determine the requirements for emergency stopping and emergency switching off. The SPA3 emergency stop safety system is designed to achieve category 2 or category B implementation as selected by the installer's risk assessment (refer to BS EN ISO13849-1:2008 para. 5.2.2.).

The connection on the SPA3 is a 9WD plug connector with the following connections:

9-pin D-plug
 Pin no.



E-STOP A1 (+24V)


Not connected








E-STOP A2 (+24 V)




Not connected




E-STOP electrical characteristics

Any emergency stop components fitted to this connector must have the following electrical characteristics:

Emergency stop system voltage : 24 V
Emergency stop system current  : 300 mA max

All connections to this connector should be fitted by a competent technician or engineer and all wires should be sleeved. Any emergency stop devices added to the E-STOP chain should meet the requirements of IEC 60947-5-1 (Low-voltage switchgear and control gear – Part 5-1: Control circuit devices and switching elements – Electromechanical control circuit devices) or UL1054 (Standard for special-use switches).

NOTE: If there are no additional emergency stop devices to be added to the system, connect pin 1 to pin 4, and pin 6 to pin 7 to permit the SPA3 emergency stop switch to function.
NOTE: If the RESET signal is not used connect pin 5 (RESET "A") to pin 9 (RESET "B").

If indicated by the user's risk assessment, a ‘manual reset' button (refer to BS EN ISO13849-1:2008 para. 5.2.2.) should be included in the emergency stop system. A reset switch is required when there is limited visibility of the danger zone from the control position. The reset switch must be positioned outside the danger zone and in a safe position from which it may be determined that no person is within the danger zone before resetting the safety system.

CAUTION: It is strongly recommended that the CMM manufacturer or retrofitter includes a periodic test of the emergency stop and, if fitted, the associated reset switch in their maintenance instructions.

E-STOP with reset implementation

There are five methods of implementing the E-STOP circuit;

Single pole E-STOP button with reset

Spa3 estop 1

Dual pole E-STOP button with reset

spa3 estop 2

E-STOP without reset implementation

Single pole E-STOP button without reset

spa3 estop 3

Dual pole E-STOP button without reset

spa3 estop 4

Bypass plug

spa3 estop 5

UCC2-2 installations

UCC2-2 installations require a special E-STOP cable (part number A-5629-0090). This cable has three tails, all marked with their function and must be installed as per the diagram below. All E-STOP schemes connect to the cable marked 'external E-STOP' including all bypass plugs.

UCC2-2 and SPA3 and E-STOP interconnection diagram