9
GB
SERIAL INTERFACE
RS-485 interface allows to connect up to 30
devices with one remote master unit.
Fig. 15 - RS-485 WIRING
The cable length must not exceed 1.5 km at 9600
BAUD.
NOTES:
1) This is an isolated RS 485 serial interface.
2) The following report describes the signal sense of
the voltage appearing across the interconnec-
tion cable as defined by EIA 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).
VOLTAGE OUTPUTS FOR SSR DRIVE
(For LFS-relay only)
Fig. 14 SSR DRIVE OUTPUT WIRING
It is a time proportioning output.
Logic level 0: Vout < 0.5 V DC.
Logic level 1:
- 14 V + 20 % @ 20 mA
- 24 V + 20 % @ 1 mA.
Maximum current = 20 mA.
NOTE: This output is not isolated.
A double or reinforced isolation between
instrument output and power supply must be
assured by the external solid state relay.
+
_
_
+
7
8
OUT 1
SOLID STATE
RELAY
5
6
COMMON
4
B'/B
B/B'
A/A'
A'/A
M
A
S
T
E
R
I
N
S
T
R
U
M
E
N
T