Rs-485 Bus System With Several Users; Synchronization - Honeywell IDENT-KEY 3 Montage, Anschluss, Anleitung

Mounting and Connection Instructions IK3 Evaluation Unit BUS-2
9.3.4

RS-485 bus system with several users

If several operating units are used, the usual RS-485
Note Chapters 9.3.1 and 9.3.2!
Example 1: The module
The end of line resistor of the
RS-485
Bus user
120 W
VT = Distributor
Example 2: The module is located somewhere between the RS-485 bus line and
beginning.
In this case, the end of line resistor of the module must be deactivated. For this
purpose,
Install a 120
RS-485
Bus user
120 W
VT = Distributor
9.3.5

Synchronization

In order to prevent densely packed readers from affecting one another, they must be connected to
one another via the "Synchronization" line (black). Up to 3 or 4 readers (depending on reader type)
can be synchronized in this manner.
Synchronization is required at a distance of
The transponder that is identified first has priority during the read/write process. The other readers
involved are inactive. After a period of 5 sec. they are reactivated.
Reader 1
bk
Synchronization line
is located at the beginning
A B
6 m max.
VT
remove both plug-in bridges
W
end of line resistor from data line A to B in the remotest distributor.
A B
6 m max.
VT
(only if supported by the
£1 m
Reader 2
bk
bus regulations are applicable.
of the RS-485
module is used (JP 15 plugged).
RS-485
Bus user
A B
VT
Bus cable 2000 m max.
from the JP15.
Module
A
B
Bus cable 2000 m max.
reader)
(approximate value).
Reader 3
bk
bus line.
Module
A
JP15
120 W
RS-485
JP15
B
not at the
RS-485
Bus user
A B
6 m max.
120 W
VT
RS-485
max. 3 or 4
Reader 4
depending
on reader type
51
bk