Interlogix NVR 21 (S/P) User Manual - Manual (Page 12)

Chapter 2: Installation
6 TruVision NVR 21(S/P) User Manual
5. Connect to an optional eSATA device such as
SATAN HDD, CD/DVD-RM.
6. Connect to a power cord.
7. Connect to speakers for audio output.
8. Connect to a VGA monitor.
9. Connect to an HDTV. The HDMI connection
supports both digital audio and video.
14. Connect up to 16 alarm inputs.
15. Connect up to four alarm relay outputs.
16. Connect to ground.
17. 8/16 PoE ports.
Wiring the keypad
The keypad uses RS-485 simplex wiring. The signal is transferred by a single twisted
pair line. A shielded STP CAT5 network cable is recommended. Ground one end of the
cable, either the first or last device on the RS-485 line.
The maximum number of devices that can be installed in one bus is 255, with a
maximum cable length of 1200 m. The cable length 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 2 below.
Figure 2: RS-485 bus serial wiring (KTD-405 keypad shown)
1. Keypad
2. I/O box 3. See section “RS-485 ports” on page 8
Use an RS-485 signal distributor for a star wiring configuration. See Figure 3 on page 7.