Rs-485 Communications - Distech Controls Security EC-BOS-602AX Hardware Installation Manual

RS-485 Communications

RS-485 Communications
An RS-485, optically isolated port is dedicated for communications to the EC-BOS
3 of the 6-position end connectors. Wiring is not necessary between modules that attach directly in-line
together—the RS-485 signal passes through the mated connectors.
Wire between device assemblies using the 6-position end connector plugs. Use shielded 18-22AWG wiring
(refer to the TIA/EIA-485 standard). Wire in a continuous multidrop fashion, meaning "plus to plus," "minus to
minus", and "shield to shield." Connect the shield to earth ground at one end only, such as at the EC-BOS
Security. See Figure 8 for example cabling.
Figure 8 RS-485 cabling between EC-BOS
Remote
Reader
Remote
Remote IO Security
Reader
RS-485 Wiring Notes
• Use shielded, twisted-pair, low-capacitance type cabling to connect expansion modules on the RS-485
trunk. Maximum cable distance is 4000 feet (1220m).
AX
At the EC-BOS Security, ground the shield wire to the grounding point at the enclosure. See
•
on page 7. Leave the shield wire at the other end of the trunk open, meaning insulate the shield wire by
taping it back or using shrink tubing.
• If connecting assemblies of modules within the same enclosure, or between adjacent enclosures (same
location), you can use a multi-pair, shielded, twisted-pair cable, for both the RS-485 and 15Vdc power and
battery backup.
Remote IO Security Module Hardware Installation Guide
Part Number 05DI-HISCRIO-22
AX
Security and expansion modules not mounted in-line.
AX
EC-BOS Security
Remote IO Security
Remote
Reader
Updated: January 2014
NOTE: Not shown is 15Vdc Power and Backup Battery
which use the other (top) 3 positions on the 6-position connector
plugs.
Shielded, twisted pair
cabling
Connect
RS-485 shield
wire to ground at
one end only.
– + s – + s
RS-485 Wiring Notes
AX
Security, on pins 1, 2, and
connections,
–
Terminals on the
+
6-position connector
s
plugs used for
RS-485 between
assemblies.
– + s
Figure 3
AX
13