Sw Itch Test - HP 3000 III Series Manual

System Verification and Troubleshooting
d. Remove the plug from receptacle Jl on the Maintenance Panel.
All lamps should go ou t., Replace the plug.
3-19. SWI'I'CH TEST. The switches on the Maintenance Panel can be
tested by placing the switch on the MPI PCA to the SWITCH TEST
position. This routes the switch information back to the Main-
tenance Panel to be displayed by lighting or extinguishing one or
more lamps for each switch. The data from the switches
~ill
be
displayed by nine groups of lamps. See figure 3-5.
The information for the REGISTER SELECTION switches is coded into
six binary bits. These bits are displayed twice by the lamps in
group five. Figure 3-5 illustrates the individual groups of
lamps and also indicates by each switch which larnp(s) will illum-
inate or extinguish when the switch is exercised.
Note
Although twelve groups of lamps are
designated in figure 3-5, not all
of the groups of lamps will be ex-
er cised d ur ing the sw itch te st.
The bistable switches, shown in the down position, will illumi-
nate the lamp/lamps indicated by the numbers above the switch
when the switch is placed up. The two-position spring return
switches, shown in the up position, will extinguish the lamps
indicated by the numbers below the switch when the switch is held
down. The three-position spring return switches (REGISTER
SELECTION switches) have a code above and below the switch that
will be displayed when the switch is held in that position.
Stenciling on the panel has not been shown for clarity. Where
two pairs of numbers are present, two lamps will be illuminated.
For example, 1,8 and 9,8 signify that group 1 lamp 8 and group 9
lamp 8 will be illuminated when the switch is exercised; the
lamps will extinguish when the switch is off. The reverse condi-
tion applies to the t~c-position spring return switches, extin-
guishing the lamps when the switch is exercised. When exercising
the REGISTER SELECTION switches, a binary coded value is present-
ed by the lamps in group five. The coded value appears twice, in
bits 0-5 and bits 8-13. The indications presented by bits 8-13
should be ignored.
I
CAUTION
I
After the switch test is complete, be sure all bistable
sw itches on the Maintenance Panel are in the down posi-
tion before restoring Sl on the MPI PCA to the
NO~lAL
position. This will prevent information from entering
the computer when the switch is returned to NORMAL.
3-28