2TLC172178M0201, rev. D
6
www.abb.com/lowvoltage
2011-11-15
Function description
The Spot light beam is supervised by the Vital 1 safety module. A unique coded signal is sent out from the control
unit to the transmitter (Spot T). The signal which comes back from the receiver (Spot R) is then compared in the
Vital 1 safety module. If the correct coded signal is received the Vital 1 switches the necessary safety output
contacts to permit dangerous machine movements.
Coding guarantees that no output signals can be produced by light from other sources, interference, or faults in
components in the transmitter or receiver. The light beam is dynamically supervised which means that if the signal
stops pulsating at the correct frequency it is immediately detected. By means of coding, the dynamic signal can
pass between up to 6 pairs of transmitters and receivers, with only one pair needing to be electrically connected to
a Vital 1.
24 VDC
This supply does not need
to be the same as
connected to the Vital 1
Vital 1 safety module
can accommodate up
to 6 Spot systems
Coded pulse transmission
Coded pulse transmission
10 m
35 m
10 m
35 m
Coded pulse
transmission
Receiver 1
Spot R
Transmitter 1
Spot T
Transmitter 2
Spot T
Receiver 2
Spot R
