DL06 Micro PLC User Manual; 3rd Edition Rev. E
4–8
Chapter 4: System Design and Configuration
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A
B
C
D
RS-232 Network
Choosing a Network Specification
The DL06 PLC’s multi-function port gives you the option of using RS-232C, RS-422, or
RS-485 specifications. First, determine whether the network will be a 2-wire RS–232C type, a
4-wire RS–422 type, or a 2-wire/4-wire RS-485 type.
The RS–232C specification is simple to implement for networks of shorter distances (15
meters max) and where communication is only required between two devices. The RS–422
and RS-485 signals are for networks that cover longer distances (1000 meters max.) and for
multi-drop networks (from 2 to 247 devices).
NOTE
: Termination resistors are required at both ends of RS–422 and RS-485 networks. It is necessary to
select resistors that match the impedance rating of the cable (between 100 and 500 ohms).
DL06 CPU Port 2
TXD+ / RXD+
TXD– / RXD–
Termination
Resistor
Signal GND
Connect shield
to signal ground
TXD+
TXD–
RXD–
RXD+
0V
TXD+
TXD–
RXD–
RXD+
0V
TXD+ / RXD+
TXD– / RXD–
Signal GND
TXD+ / RXD+
TXD– / RXD–
Signal GND
RTS+
RTS–
CTS+
CTS–
RTS+
RTS–
CTS+
CTS–
DL06 CPU Port 2
1
6
11
1
6
11
5
10
15
5
10
15
The recommended cable for
RS422 is AutomationDirect L19954
(Belden 9842) or equivalent.
RXD+
RXD–
TXD+
TXD–
Signal GND
PORT 2
Master
9 TXD+
10 TXD–
13 RXD+
6 RXD–
1 1 R TS+
12 R TS–
14 CTS+
15 CTS–
7 0 V
T ermination
Resistor at
both ends of
network
The recommended cable for RS422 is
AutomationDirect L19772 (Belden 8102)
or equivalent.
Signal GND
RXD
TXD
TXD
RXD
GND
RTS
CTS
RTS
CTS
RTS
CTS
OR
Loop
Back
PORT1
6P6C
Phone Jack
Point-to-point
DTE Device
Signal GND
RXD
RXD
TXD
TXD
0V
1
4
3
1
6
11
5
10
15
Connections on Port 2
Connections on Port 1
RS-422 Network
RS-422 signals are for
long distances ( 1000
meters maximum).
Use terminator
resistors at both ends
of RS-422 network
wiring, matching the
impedence rating of
the cable (between 100
and 500 ohms).
RS-485 Network
RS-485 signals are for
longer distances (1000
meters max) and for
multi-drop networks.
Use termination
resistors at both ends
of RS-485 network
wiring, matching the
impedance rating of
the cable (between
100 and 500 ohms).
Normally, the RS-232
signals are used for
shorter distances (15
meters maximum),
for communications
between two devices.