Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F
9-33
The purpose of this section is to determine if the computer subsystem electronics hardware are
working properly. Assessment will be made at the board level.
9.3.1.1 Front Panel Display
The front panel display is a 2 line by 40 character display. It has its own microprocessor to
decode commands and display characters. It contains a self test feature. To test the display:
1. Turn off the power to the instrument.
2. Fold down the M200AU front panel
3. Disconnect the 26 line flat ribbon cable (J2) that connects the computer parallel port to
the keyboard.
4. Turn on the M200AU power switch.
5. Observe the front panel display. If the display successfully completes its power on self
test, it will display a single underline character "_" in the left most character of the top line of
the display. If this character is present, the display is working properly.
6. Power down the analyzer, and re-attach the cable to J2, and proceed to the next test.
9.3.1.2 Single Board Computer
The SBC40 is a full function computer designed for instrument control applications. It consists
of a 16 bit V40 microprocessor, 2 serial and one parallel ports, Standard Bus interface, and 4
sockets for memory. The memory sockets consist of: 256k ROM containing the multitasking
operating system and application code, 8k EE prom containing the setup variables, a 128k RAM
and time-of-day clock to provide event timing services, and a second 128k RAM. The overall
function of this board is quite complex, therefore, complete testing is not possible in the field.