Diagnosing RS-232 connections

The cu connection test

You can use the cu connection test to diagnose RS-232 connections.

Before using the cu connection test:

You must have the UUCP subsystem installed. Use the SGI utility inst and load the eoe2.sw.uucp subsystem.
Make back-up copies of the following three files:

/usr/lib/uucp/Systems
/usr/lib/uucp/Devices
/usr/lib/uucp/Dialers

Put the following contents in each file:


File
/usr/lib/uucp/Systems	[leave empty]
/usr/lib/uucp/Devices	Direct port - Any direct
/usr/lib/uucp/Dialers	direct

port should be replaced with ttyd1 if serial port 1 is being used, or ttyd2 if serial port 2 is being used. Assign read/write permissions to the serial port with the UNIX command:

chmod 666 /dev/ttyd1         (for port 1)
chmod 666 /dev/ttyd2         (for port 2)

Establishing a test connection:

Log in as root.
To use port 2, enter:

cu -l /dev/ttyd2 -s 9600

If using port 1, use ttyd1.

You should receive the message:

Connected.

If this message does not display, review the steps for using the cu connection test.

Enter the test sequence. Sample test sequences are given in the next section.

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