6500 Test Functions

10/19/92

The 6500 has two levels of built in RS232 diagnostics. The first level is run every time the instrument is powered up. This level does a check of the UART, and displays the message:

RS232: AVAILABLE

on the third line of the crt if all goes well. If the UART is found not to be OK the message:

RS232: BAD UART

will be displayed. If you get the "BAD UART" message you should contact Frye Electronics as you probably have defective hardware.

The second diagnostic is run if the loop-back plug (furnished with the RS232 option) is plugged into the back of the instrument. This test checks the UART more completely, checks the RS232 driver chips, the cable from the rear panel DB25 connector to the I/O board, and the RS232 interrupt. This diagnostic test displays:

RS232: DIAGNOSTICS PASSED

if all goes well. It will display:

RS232: NO INTERRUPT

if the interrupt jumper is missing, incorrectly plugged in, or if the trace on the back of the board is not cut. It displays:

RS232: BAD CABLE

if the cable from the I/O board to the rear panel is plugged in backward.

If level two diagnostics are run, it is recommended that the machine be turned off, the loop-back plug removed, then operations restarted as the serial port may not be correctly initialized.

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