4.3 RS-232
Cables
4.3.1
RJ-45 to DE-9S DTE
This cable is used to connect from an RJ-45 based RS-232 port on the SCADAPack 32P controller to
DE-9P connector on a DTE such as a PC. A 10 ft. long cable is available from Control Microsystems
as part number 297217.
RJ-45
8 Pins
SCADAPack 32P
DTE Function
DE9S
DTE
Function
DE9S
Shield connects to shell
6 TxD
RxD
2
5 RxD
TxD
3
4 GND
GND
5
1, 2, 3, 7 and 8
are not connected
at this end.
GND
GND
No wires connected at
this end.
4.3.2
RJ-45 to DE-9P DCE
This cable is used to connect from an RJ-45 based RS-232 port on the SCADAPack 32P controller to
DE-9S connector on a DCE such as a modem. A 15 inch long cable is available from Control
Microsystems as part number 297218.
RJ45 SCADAPack
32P
DTE Function
DE-9P DCE
Function
DE-9P
Shield connects to shell
3 DTR DTR
4
6 TxD TxD
3
5 RxD RxD
2
2 DCD DCD
1
4 GND GND
5
7 CTS CTS
8
8 RTS RTS
7
1 +5V +5V
9
4.4
RS-485 Serial Communication Port
Serial port COM1 on the SCADAPack 32 controller may be configured as an RS-485 serial
communication port. A jumper must be installed on J9 to operate COM1 in RS-232 mode. Refer to
section
When configured as a RS-485 port COM1 transmits and receives differential voltages to other RS-
485 devices on a network. The RS-485 specification allows a maximum of 32 devices connected on
a single RS-485 network. The recommended specification for RS-485 is the cable length should not
exceed a maximum of 4000 feet or 1200 meters. Termination resistors are required when using long
cable lengths and high baud rates. Refer to section
information on termination resistors.
The signal grounds of the RS-485 devices in the network are not connected together but instead are
referenced to their respective incoming electrical grounds. The grounds of the RS-485 devices on the
network must be within several volts of each other.
SCADAPack 32P Controller Hardware Manual
May 26, 2006
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