GPD315 Modbus RTU Technical Manual TM 4325
Page
3
The function of terminals R+, R-, S+, and S- are described below.
Table 2-1. Functions of Terminals
Terminal Symbol
Functions
Remarks
S+
RS-485 output (+)
Use as output at
S-
RS-485 output (-)
parallel connection
R+
RS-485 input (+)
Us as input at
R-
RS-485 input (-)
parallel connection
It is important to select an appropriate wire size to prevent voltage drop. The table below
indicates the suggested wire sizes.
Table 2-2. Applicable Wire Size for Terminal Connections
[mm
2
]
AWG
I [A]
VAC [V]
Twisted wire
1.0
16
12
125
Single wire
1.5
16
12
125
UL
-
22-16
10
300
CSA
-
28-16
10
300
CSA
-
28-16
10
150
When stripping the wire, approximately 5.5 mm should be exposed in order to make a good
connection.
Note: Avoid sources of electric interference capable of inducing noise into the cable.
Communication and signal wiring should be kept separate from power wiring. Four inches should
separate the communications/signal wiring from any low voltage AC or high frequency source.
Ten inches should separate the communications/signal wiring from any high voltage cables. If
communication or signal wiring must cross power wiring, it must cross at a right angle.
