2 Connection to the multidrop bus
2.1
SUB-D connector pinout
The RS 485 standard transmission interface is electrically isolated from the XG field station.
It is available on a 15-pin SUB-D connector using cable W 814 940 940 111
(supplied with the station).
I
S
H
E
N
G
L
5
9
4
8
3
7
2
6
1
0 V
D (A)
5
4
3
2
1
8
7
6
11
10
9
15
14
13
12
D (B)
2.2
Connection to the standard RS 485 bus
Pins to be used :
SUB-D connector (15-pin) Control system
RX
E
0V
R
PG
0V 15
D(B)
D(A)
14
7
*
PG
0V
Zt
RXD+
A'
RXD-
B'
R
TXD+
A
TXD-
B
E
120 Ω
1 nF
Zt line terminator recommended at both ends
(*) : Connection of the shielding at both ends depends on the constraints imposed by the installation.
7
2 Connection to the multidrop bus
2.3
Recommendations
I
S
H
E
N
G
L
CAUTION
ELECTROSTATIC CHARGE
This products contains sensitive electronic components.
Set switches with unit switched off.
Failure to follow this instruction can cause equipment damage
• Use a shielded cable with 2 pairs of twisted conductors.
• Connect the reference voltages together.
• Maximum length of the line : 1000 meters.
• Maximum length of a tap link : 20 meters.
• Do not connect more than 28 stations on one bus.
• Cable routing : Keep the bus away from the power cables (at least 30 cm).
• Any crossovers should be at right angles, and the cable shielding must be connected to the ground of each device.
• Fit a line terminator at both ends.
Various accessories are available for connecting the devices.
Cables for bus TSX-CSA… sold in 100, 200 or 500 m lengths.
TSX-SCA62 subscriber socket
This passive unit comprises a printed circuit fitted with a screw terminal block for connecting 2 devices to the bus.
It includes a line terminator when placed at the end of the line.
The switches on the socket must be set in the following way :
Switch number
2
3
5
Switch position
OFF
OFF
OFF
The position of the other switches has no significance.
8
2 Connection to the multidrop bus
2.4
Example of connection to a UNI-TELWAY bus
TSX-SCY 2160 X
W 814 940 940 111
TSX-SCY CU 6530
TSX-SCA62 TSX-SCA62
W 814 940 940 111
I
S
H
E
N
G
L
9
