Super Systems 7SL - Manual (Page 11)

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D) Serial Interface
For units built with optional RS-485 communication
The RS-485 interface can connect up to 31 instruments
with the remote master unit (see below).
Maximum cable length: 1.5 km (9/10 mile) at 9600 baud.
NOTE: According to EIA specification for RS-485:
a) The “A” terminal of the generator shall be negative
with respect to the “B” terminal for a binary 1
(MARK or OFF) state.
b) The “A” terminal of the generator shall be positive
with respect to the “B” terminal for a binary 0
(SPACE or ON) state.
I
N
S
T
R
U
M
E
N
T
12
13
COMMON
11
M
A
S
T
E
R
12
13
11
I
N
S
T
R
U
M
E
N
T
B'/B B/B'
A/A' A'/A
12
13
COMMON
11
M
A
S
T
E
R
I
N
S
T
R
U
M
E
N
T
B'/B B/B'
A/A' A'/A
7sl-1-00.p65 9/17/02, 2:39 PM 11