Table of Contents
Advertisement
2.6.
Serial RS485 Wiring Diagram
Up to 31 controllers may be connected in parallel on phy-
sical line RS485, independently of which option is selected
(Master Modbus (G), rete bridge RS485 (ME), Modbus RTU
Slave (M0) ); they may even be of different models.
The line must be terminated with a resistor (120 Ω, 1/2 W) at
each end.
Host computer
RS485
B (+)
A (-)
120
Frame ground (FG)
Figure 13 - RS485 connection for 850 controller with optional communication (M) = M0
Host computer
RS485
B (+)
A (-)
120
Frame ground (FG)
Figure 14 - RS485 connection for 1650 and 1850 controllers with optional communication (M) = M0
Shield
+
-
19
18
20
17
21
16
22
15
850
No. 1
Shield
45
28
46
27
+
47
26
-
48
25
1650 - 1850
No. 1
80209C_MHW_850-1650-1850_20-2020_ENG_pag. 40
Output 1 type G options have an integrated 120 Ohm termi-
nation, while options M0 and ME require addition of termina-
tion outside the instrument.
7
6
8
5
9
4
10
3
4
3
2
1
120
1/2 W
120
1/2 W
+
-
19
18
7
20
17
8
21
16
9
22
15
10
850
No. 31
45
28
46
27
+
47
26
-
48
25
1650 - 1850
No. 31
6
5
4
3
4
3
2
1
Advertisement
Table of Contents
