Guidelines Rs-485 And Ib2 Bus; Bus End Of Line Resistors; Cable Lengths - Honeywell IB2 Mounting And Connection Instructions

Mounting and Connection Instructions IB2 Bus Expander
5.3

Guidelines RS-485 and IB2 bus

5.3.1

Bus End of line resistors

With jumpers JP1 to JP4 the EOL resistors of the
jumper JP5 the EOL resistor of the
Basically note : The bus line must be terminated at
first user RS-485 / IB2
A
B
- The user is at the beginning or end
—> Activate EOL resistor
- The user is between the beginning or end
the line:
—> Deactivate EOL resistor
Procedure:
Activate EOL resistor:
Set both jumpers
Deactivate EOL resistor:
Remove both jumpers
Attention!
Important for BUS-2 interfaces
On BUS-2 interfaces the EOL resistors must be
deactivated.
Remove jumpers if required (JP1 – JP4).
5.3.2

Cable lengths

Control
panel
R120
A B
(EOL)
IB2 BUS interface is activated/deactivated.
RS-485 / IB2
user
max. 2000 m
of the line:
RS-485 / IB2
User
A B
max. 5 m
max. 2000 m
4 RS-485 interfaces are activated/deactivated, with
both ends with 120 Ohm
user
IB2 BUS
from panel
of
JP1–4
JP1–4
Out1
RS-485 / IB2
RS-485 / IB2
User
RS-485 / IB2
User
max. 5 m
.
RS-485 / IB2
user
JP5
IB2 BUS
Out1 Out2 Out3 Out4
JP1 JP2 JP3 JP4
Out2 Out3
4x BUS-2 / RS-485
User
RS-485 / IB2
A
17
last user
Out4
User
R120
B