Safety beams

Standard beams

FA31 is a standard wiring infrared beam powered on both sides.  FA33 is a version in the same housing with a battery powered transmitter.

As a standard wiring photobeam, FA31 can be used to replace most automatic photobeams. The slim body ensures the beam can be placed at the very edge of an opening. The PCB can be set to face forwards or to either side. Both receiver versions need a 12-24V supply. The output relay can be set to N/O or N/C. 

FA33 transmitters may run on battery or 12Vdc (not both). They have two power settings for 5m or 10m range. The CR123A battery has a theoretical 50,000 hours lifetime. 

FA33 Tx

Operating Voltage 12V-24V AC or DC,
IR range FA31 18m
FA33 5m (lo) 10m (hi)
Beam splay -10dB @ 5 degrees
FA33 Tx current 60uA (hi) 30uA (lo)
Dimensions 37.5mm x 36mm x 108mm
Relay contacts 150mA @ 30V ac/dc Form A or B


FA31 and FA33 beams can be combined. This diagram shows two beams wired into a N/C safety input. Both contacts must be set to N/C on the Rx jumper. Note the transmitters are set on opposite side of the drive so they do not interfere.

DSA infrared curtains

There are some automation systems, particularly sliding gates, that have so many shear and draw in risks, that the only solution is to block protect the area.

DSA creates a matrix of infrared beams across entrances up to 30m for comprehensive safety.

DSA8 has 8 primary beams and 12 interlacing beams. DSA10 has 10 primary beams and 16 interlacing beams.

DSA setting

There are three emitter powers set on jumper links on the master and slave marked S, M, and L.

The transmitter LED flashes when one beam is blocked, or lights solid when 2 neighbouring beams are blocked. The relay activates when the LED lights solid. The receiver’s red LED lights only when one of its own receivers is blocked.

DSA's are mounted vertically with horizontal beams. They can be either way up (but must be the same). LED beam spread is narrow so master and slave need to be at the same height.

The aluminium body rotates through 270 degrees, so the mounting surface may be at an angle. There is a buzzer in the master to help alignment. 

Power Supply 10-18 volts DC
Operating Temp -30°C to 70°C
Response time <40ms
Beam separation 125mm
Operating Current 64mA max
Iq=45-51mA standby
Dimensions 35mm x 36mm section
length 1.4m or 1.7m
Coverage 10m to 30m, 270 degrees
Relay contacts 1A @ 30Vdc, Form A or B

Tx and Rx both have a red flashing LEDs. When the beam is blocked, an LED on RX flashes every 3 secs. When unblocked LED flashes 4 times then pauses. Receiver also has a red LED that is on when the photo beam is not interrupted


DSA wiring

Standard wire colours are shown clarity and diagnosing problems. The transmitter and receiver sides are powered the same (RED & BLACK). The WHITE sync’ wire RT  runs from one side to the other. Relay contacts on the transmitter side are shown wired in YELLOW & BLUE. NC or NO are set by an internal jumper. NC is fail safe.