Status Indicators

Inputs -   Green LED ON when input is ON
Outputs - Green LED ON when input is ON
Reset -    Yellow LED ON when reset input is ON (Auto reset mode LED ON continuously)
EDM -      Yellow LED ON when EDM inputs are ACTIVE
Status -   RED LED's ON steady when the system is OK
                RED LED's flash ON/OFF when the system is in lockout

Wiring Information

Terminals A1 and A2 – Power supply input - Connect a suitably stabilized 24V DC power supply
to terminals A1 = +24V DC and A2 = 0V DC. The current consumption of the MFU with no load
applied on the output switching terminals is 150mA.

Terminals A3 and A4 – External device monitor (EDM) - Normally closed switch contacts, in
series from the external power switching devices are connected across terminals A3 and A4.The monitoring circuit checks that the power switching devices both de-energize at the same time the
MFU safety output switches de-energize. If one or both of the power switching devices fail to de-energize at this time the MFU goes into a lockout condition, turning all output switches off.

To reset from a lockout condition it is necessary to remove the 24V DC supply from the MFU and
then re-apply.

If the EDM circuit is not used it is necessary to link terminals A3 to A4 otherwise the system will go
to a lockout condition at the next demand upon the safety system.

Terminals A5 and A6 – Safety output 1 switch contact - Connect terminals A5 and A6 to one channel of a machine’s stop circuitry. For example, via an external power-switching relay or directly
to a safe PLC input or machines final control element.

Terminals A7 and A8 – Safety output 2 switch contact - Connect terminals A7 and A8 to one channel of a machine’s stop circuitry. For example, via an external power-switching relay or directly
to a safe PLC input or a machines final control element.

If a single channel safety circuit is used link terminals A6 and A7. Terminals A5 and A8 are then connected to the machine’s safety circuit. Connecting in this way links safety output switch 1 and safety output switch 2 in a series configuration.

Terminal A9 – No connection

Terminal A10 – Auxiliary electronic switching output 1 - The Auxiliary switching output should
only be used for non-safety critical application. For example connecting an indicator lamp or as feedback to a PLC to confirm the safety outputs have de-energized

Terminal A11 – Auxiliary electronic switching output 2 - The Auxiliary switching output should
only be used for non-safety critical applications. For example connecting an indicator lamp or as feedback to a PLC to confirm the safety outputs have de-energized.

Auxiliary outputs 1 and 2 both energize when safety output switches 1 and 2 energize and both de-energize when the safety outputs de-energize. Auxiliary outputs ON = 24V DC and OFF = 0V DC.

Terminal A12 – Reset - If the MFU is required to be in the latch mode a suitable switch should be connected between terminal A12 and the 24V DC supply. If the safety output relays de-energize a depression of the switch is required to re-energize the output switches to an ON condition.

The MFU’s safety output switches will only re-energize when the reset switch is depressed and then released.

If the MFU is required to operate in an automatic reset condition do not connect a switch to
terminals A12.However, it is necessary to link terminal A12 to terminal A10 before an automatic
reset condition can be established.

Terminal B1 and B2 – light curtain 1 inputs (OSSD1 and OSSD2) - Connect the electronic output switches (OSSD1 and OSSD2) of a 1000 Series light curtain to terminals B1 and B2 respectively.

Note: An internal circuit monitors disparity between the two input channels. If the inputs do not
switch together (within 100ms of each other) the system will go into a lockout condition.

Terminal B3 and B4 – light curtain 2 inputs (OSSD1 and OSSD2) - Connect the electronic output switches (OSSD1 and OSSD2) of a 1000 Series light curtain to terminals B3 and B4 respectively

Note: An internal circuit monitors disparity between the two input channels. If the inputs do not
switch together (within 100ms of each other) the system will go into a lockout condition.

Important: If either terminal B1/B2 or, B3/B4 are not used; for example, if only one light curtain is employed for a particular application, it is necessary to link the unused input terminals to the 24V DC supply. If not the MFU’s output switches will not energize.

Terminals B5/B6 and B7/B8 – dual channel emergency stop circuit - Connect one channel of
the machines emergency stop circuit between terminals B5 and B6 and the second channel between terminals B7 and B8.

Note: An internal circuit monitors for short circuits and switching disparity between the two input channels. If the inputs do not switch together (within 100ms of each other) the system will go into
a lockout condition. This configuration meets the requirements for ‘control reliability’ and cannot be used in a single channel configuration.

Important: If the emergency stop inputs are not used it is necessary to link terminals B5 to B6 and terminals B7 to B8. If not the safety output switches will not energize.

Terminals B9 and B11 – 24V DC supply - Additional + 24V DC outputs for connecting to the light curtains etc.

Terminals B10 and B12 – 0V DC supply - Additional 0V DC outputs for connecting to the light curtains etc.