User Manual

I/O Ports
December 2007 Revision 3.5 29/48
8.2.3 Output Configurations
When an I/O port is configured as an output, the V
IN
signal must be connected to a supply to pull
up the I/O port when it is not activated. Setting the I/O port pulls down its output to the GND. V
OUT
supply may be used to supply V
IN
signal and the external load. The following examples show how
to connect a load (a relay, a light, etc.) to the TR-L100 Reader using the internal supply (V
OUT
) or
an external supply.
Figure 13: Connecting a load using the internal supply (V
OUT
)
TR-L100 Reader
Ground
V
OUT
V
IN
I/O
Load
-
+
Using an external supply
Figure 14: Connecting a load using an external supply
TR-L100 Reader
Ground
V
OUT
V
IN
I/O
Load
-
+
+28 V
0 V
When the I/O port is set, the relay is activated. When the I/O port is reset, the relay is not activated.