Connections to COM2 are made through a RJ-45 modular connector. COM2 supports six signals
plus Ground and 5V power. The following diagram shows the pin connections for the RS-232 (RJ-
45) port connector for COM2.
RJ-45 Modular Jack
1.
+5V
2.
DCD
3.
DTR
4.
GND
5.
RxD
6.
TxD
7.
CTS
8.
RTS
2
1
8
7
6
5
4
3
Figure 12: RJ-45 Connector Pinout
Notes:
•
The transmitters used in COM2 generate RS-232 compatible
±
5V levels. Cables should be
limited to a maximum of 10 ft (3m).
•
For RS-232 operation (RxD) J13 must have the jumper link in position “RS-232”
The following table provides a description of the function of each pin of the RJ-45 connector. In this
table a MARK level is a voltage of +3V or greater and a SPACE level is a voltage of –3V or lower.
Pin
Function
Description
1 5V
(Output)
This pin can be connected to the 5V power supply by
installing a jumper at J14 on the SCADAPack 350.
Warning:
This 5V output is used to power Vision terminals
and other Control Microsystems accessories. DO NOT apply
5V to this pin. Ensure that cables connecting this pin do not
have any voltage.
2 DCD
(Input)
The DCD led is on for a MARK level.
3 DTR
(Output)
This pin is normally at a MARK level.
This pin is at a SPACE level when DTR is de-asserted.
4
GND
This pin is connected to the system ground.
5 RxD
(Input)
The level is SPACE on standby and MARK for received
data.
The LED is lit for a MARK level.
6 TxD
(Output)
The level is SPACE on standby and MARK for transmitted
data.
The LED is lit for a MARK level.
7 CTS
(Input)
This level must be a MARK for the communication port to
transmit data. When the attached device does not provide
this signal, the controller keeps the line at a MARK.
SCADAPack 350 Hardware Manual
February 14, 2007
30
