IBM 865951Y - Netfinity 5000 - 51Y, Hardware Maintenance Manual

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Serial port connectors
Serial ports are used to communicate with printers,
plotters, external modems, auxiliary terminals, and other
computers. The server provides two serial ports (A and
B), and a special type of serial port (Management Port C,
described on the next page). You can add more serial
ports by installing a serial adapter in one of the expansion
slots.
Note
Serial port A can be shared by the system
management processor and operating system. Serial
port B is used by the operating system only.
Management port C is controlled exclusively by the
system management processor, cannot be used by
the operating system, and cannot be configured using
the Configuration/Setup Utility program. See the
“Advanced System Management Information” section
of this
Server Library for information about configuring
serial ports A and C.
Serial ports transfer data asynchronously; they can
transmit any number of bits at any time, with no restriction
on the duration of the pauses between characters.
The serial ports transmit and receive data and commands
at a rate of 300 bits per second (bps) up to 115 200 bps.
The bits-per-second measurement is commonly referred to
as the
baud rate.
Each of the two serial connectors provided on the Netfinity
5000 uses a 9-pin, D-shell connector.
1 5
6 9
Table 10 shows the pin-number assignments for the serial
port connectors. The pin-number assignments conform to
the industry standard.
Table 10. Serial Port Connector Pin-Number
Assignments
Pin Signal Pin Signal
1 Data carrier detect 6 Data set ready
2 Receive data 7 Request to send
3 Transmit data 8 Clear to send
4 Data terminal ready 9 Ring indicator
5 Signal ground
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