6
Logic Outputs
There are 6 logic outputs, also known as “General Purpose Outputs” or
“GPO”. They are used to control LED’s or relays. The logic output can source
10mA at 5V DC, or sink 60mA up to 50V DC�
A high sensitivity relay (such as a reed relay) can be driven by connecting
multiple logic outputs in parallel� In the diagram to the right, this arrangement
will develop 4V across a 500-Ohm coil, providing that all four outputs are
activated simultaneously�
LED
relay
When sourcing from the Logic Output, an LED connected
between one output (Anode, A) and common (Cathode,
K) will illuminate when the logic output is activated,
without requiring any external current limiting resistor (the
Soundweb London contains an internal 440 Ohm resistor)�
Port 1
Current source, 10mA max
LED
LD5
For higher current reed type relays you must use the Logic Output
to sink current using an external power supply�
Port 1
Current sink, 60mA max
External supply
VCC
Opto Output
In addition to the six standard logic outputs, there is
an isolated output, which fails safe (open circuit) if the
unit becomes faulty�
relay
+supply voltage
ground
