Rs485 Wiring Overview - Lutron GRAFIK 7000 Guide D'installation Et De Maintenance

RS485 Wiring Overview

RS485 wiring is the PELV (Class 2: USA) wiring
used for the following links:
• Control station device (CSD) link(s)
• Local zone controller (LZC) link(s)
• Power panel (PP) link
• Interprocessor (IP) link
(if not using the Ethernet wiring option)
• User interface (UI) link
(if not using the Ethernet wiring option)
• Auxiliary (AUX) link
Specifications and Notes
• Do not run PELV (Class 2: USA) RS485 wiring
in same conduit as line (mains) voltage wiring;
follow all applicable local and national electrical
codes
• Each link must be daisy-chained; do not
home-run wiring to individual devices
• The processor panel does not need to be at
the end of any RS485 link (see drawing)
• Use a link terminator (LT-1) at each end of each
RS485 link, with the exception of the LZC
links, which do not require link terminators
• Connections to numbered terminals are wired
1 to 1, 2 to 2, 3 to 3, etc. on each of the CSD,
PP, and IP links
• Total length of any RS485 link may not be
more than 2000 ft. (610 m). This distance is
based on proper shielding of the twisted
shielded pair, #12 AWG (4.0 mm
terminal 1 and terminal 2 of the CSD link, and
the use of a link terminator (LT-1) at each end
of each non-LZC link
• If #12 AWG (4.0 mm 2 ) wire is not used on
terminals 1 and 2 of the CSD link, the
maximum CSD link length must be de-rated;
see chart. Length of LZC, PP, IP, and UI links
do not need to be de-rated if smaller wire sizes
are used on terminals 1 and 2
Caution! If link terminators (LT-1) are not
used when needed, or improper wiring
topology is employed, the system may
not communicate reliably.
2 ) wire to
R
2000 ft (610 m) max.
CSD
LT-1 CSD
Example of daisy chain wiring:
Do not home-run individual device wiring.
Processor panel may be located at any point on link.
• A link booster (MX-RPTR) can be used to
increase the CSD or PP link length by another
2000 ft. (610 m), to a maximum of 3 link
boosters and 8000 ft. (2 440 m); link boosters
cannot be used on LZC links
• RS485 communication is a stream of low-
voltage data. Suggestions listed on this page
help to keep that communication reliable:
- Proper shielding blocks noise
- LT-1 termination stops "data reflection" from
corrupting data on the link
- Daisy-chaining eliminates multiple "data
reflection" paths
- #12 AWG (4.0 mm
2 of the CSD link minimizes power loss to the
CSDs
Terminals 1 & 2
Wire Sizes
#12 AWG (4.0 mm
#14 AWG (2.5 mm
#16 AWG (1.5 mm
#18 AWG (1.0 mm
Installation of GRAFIK 5000/6000/7000 System
CSD CSD
CSD
G7000P
2 ) wire on terminals 1 and
Maximum CSD
Link Length
2 ) 2000 ft. (610 m)
2 ) 1400 ft. (425 m)
2 ) 900 ft. (275 m)
2 ) 600 ft. (180 m)
LT-1
11