HP 5890 SERIES II Service Manual page 16

The Minus key decrements the address.
The ENTER key switches the type of value presentation. The binary display mode can be entered from
the hexadecimal mode by pressing . If already in the binary mode, it will return to the hexadecimal
mode.
The binary mode is very similar to the hexadecimal mode except that the value of the address, and only
that value (one byte), is displayed in the binary code. If the next value (one byte in binary) is desired,
simply increment the address, which is always displayed in hexadecimal. The incrementing and decre-
menting of addresses in the binary mode are done in the same manner as in the hexadecimal mode.
To leave this Display Memory routine, press any of the instrument function keys. This also reestablishes
the normal key definitions.
Calib and Test (Clear Dot 5) SelfTest
This instrument test is exactly the same as the one that occurs automatically at power turn on, except it
is entered whenever the operator decides. It is initiated from the keyboard by pressing: The first indica-
tion a user has that the instrument is working is when the unit tests its RAM (Random Access Memory)
and the visual display portion of the front panel. The entire visual display (all possible dots) and all LEDs
turn on for a few seconds.
The next indication is when the unit displays TESTING MEMORY. During this time, the unit tests most
of the processor memory (ROM) circuits. Note that during this time only the NOT READY LED remains
lit.
The third indication is when the unit displays TESTING SIGNAL PATH. During this phase of the selftest,
the unit actually exercises most of the signal handling sections of the Main Board. Note that the analog
sensors (i.e., temperature sensors) are NOT tested at this time; they are tested after the selftest. How-
ever, by linking the A/D through the CPU to the D/A and by looping the D/A output back as an input to
the A/D, most of the Main Board' s signal handling circuits are checked.
The fourth (and unless an error is found, the final) indication is the PASSED SELFTEST message. This
message verifies that the selftest sequence has been completed. The PASSED SELFTEST display re-
mains until some further action is taken by the operator or some area not tested during the SelfTest is
detected.
By pressing the clear key, the visual display should change to some message about OVEN TEMP . This
action, with its resulting message, verifies that the keyboard is communicating with the CPU.
Calib and Test (Clear Dot 7)
HPIL Loopback Test This diagnostic test requires that one of the HPIL cables be connected from the
OUT to the IN. The test is then initiated from the keyboard by pressing: By entering this test, 128 frames
will be transmitted from the CPU through the Communications Interface Board. With the HPIL cable in-
stalled, the same word should be transmitted back to the Z80 processor, sensed and compared with
the transmitted word. If the comparison verifies correct transmission and reception, a PASSED SELF-
TEST message will be displayed on the instrument' s front panel visual display. Note that this is the
HPIL SelfTest and is not the same as the instrument SelfTest done at power turn on.
If a component failure exists in the HPIL circuitry, or if either the Interface Board or HPIL Cable is not
properly installed, a FAILED SELFTEST message will be displayed.
SVC 1- 9
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