Connecting The Rs-232 Port - Alpha Technologies CFR 7.5K Operator's Manual

2.9 Connecting the RS–232 Port
The unit can be remotely setup, monitored, and tested by connecting the unit's DB–9 connector
to a computer's serial port (Figure 2.5) or communication via a LAN with an optional SNMP
agent. Windows HyperTerminal or any other terminal emulation program is used to communi-
cate with the unit. Section 4 gives more information.
The DB–9 port is a standard feature, but its configuration is different depending upon if a SID or
IID display panel is installed on the unit.
TIPS:
1) The cable must be less than 50 ft. (15m). long and it must be shielded to meet EMI
requirements.
2) The RS–232 is not isolated. Signal ground is directly connected to the internal logic
ground. Contact Alpha if the external battery connector must be referenced to positive
ground instead of negative ground (the factory default).
GND RXD TXD
5 4 3 2 1
9 8 7 6
CTS RTS
FOR USE WITH IID
EQUIPPED UNITS
Connecting Units With an SID Display Panel:
• It uses a basic 3-wire line with software handshaking (XON / XOFF).
• Figure 2.5 shows how to connect the RS–232 port to a standard PC serial port.
• The parameters are: 1200 baud, 8 data bits, no parity, 1 stop bit.
Connecting Units With an IID Display Panel:
• The IID RS–232 port uses a nonstandard cable with RTS/CTS signal straight through
and RX/TX signals reversed.
• The baud rate is operator-configurable.
• For further information on IID RS–232 applications refer to "Information Management
Using the Intelligent Interface Device" manual (Alpha manual # 018–029–B0–001).
25
1
TXD 2
RXD 3
4
GND 5
6
RTS 7
CTS 8
9
UNIT RS-232 9-PIN IBM PC
SERIAL CONNECTOR SERIAL PORT
(9-PIN FEMALE)
Figure 2.5
RS–232 Wiring Diagrams
1
TXD 2
2 RXD
RXD 3
3 TXD
4
4
GND 5
5 GND
6
6
RTS 7
7 RTS
CTS 8
8 CTS
9
9
UNIT RS-232
SERIAL CONNECTOR
(9-PIN FEMALE)
2 Installation
1 1
2 TXD
3 RXD
4 RTS
5 CTS
6
7 GND
24
25
25-PIN IBM PC
SERIAL PORT