GeoVision GV-AS2120 IP Control Panel - Manual (Page 129)

GV-EV48 Controller
127
6
4
7
6.2 Installation
6.2.1 Connecting RS-485 Card Readers
With a single RS-485 cable, you can connect up to 2 GV-Readers and / or GV-GF
Fingerprint
Readers to the RS-485 interface on GV-EV48.
Up to 2 GV-Readers and
GV-GF Fingerprint Readers
Load
Default
2 1
NO
BAT- BAT+ GND +12V
B- B+ A- A+ B A
Terminal
Resistor
RS485
Figure 6-2
To connect to GV-CR420 or GV-GF1921 / 1922 through network connection, refer to
8.3.1
Extended Reader
for details.
Note:
When the RS-485 connection between GV-EV48 and the reader is over a long
distance, you can turn ON the RS485 A Terminal switch if the signal is unstable.