GE TLE Scalable 40, User Manual, Page: 13 / 118

TruVision DVR 40 User Manual 7
Camera Switch setting
Legend Protocol DIP
switches
5
Address DIP
switches:
0000
Wiring the TVK-505U keypad
The TVK-505U keypad uses RS-485 simplex wiring. The signal is transferred by a single twisted pair
line. An unshielded CAT5 network cable is recommended for normal applications. Use a shielded CAT5
cable if the cables could be exposed to interference.
The maximum number of TVR 40s that can be installed in one bus is 31, with a maximum cable length
of 1200 m. Both can be expanded using a signal distributor.
Both the first and the last device in series should be terminated with 120 Ohm resistance to minimize
line reflections. See Figure 6 below.
Figure 6: RS-485 bus serial wiring
1. TVK-505 keypad; 2. I/O box; 3. TVR 40