Honeywell 6000 Series Reference Manual page 52

Table 3 -2 (cont). DSU 190 Controls and Indicators
CONTROL OR INDICA TOR
Unit Number Indicator
SELECT LOCK switch!
indicator
. LOCAL indicator
TEMP indicator
WRITE PROTECT switch!
indicator
FUNCTION
Lights when the heads are loaded. indicating which unit is
online. Unit nutnbers are installed by installation personnel
and should not be changed.
Lights when one or more of the following fault conditions
occur:
1. Read or Write is selected without an On Cylinder signal
Z. Low voltage (±5V. ±20V, or -16V) signal
3. Read and Write are selected at the same time
4. Servo digits lost for more than 200 milliseconds (heads
automatically unload)
5. More than one head is selected
6. Head Register contains number exceeding 18 (No Head
Select)
7. Write com.rnand without write current
8.
Write current without Write command
9. Write current without write data
Conditions 5 through 9 are known as current faults. They
are inhibited while writing address marks.
All conditions require that the SELEC T LOCK switch be
pressed or that the controller ij:;sue a DIN.
Lights when drive experiences either of the following
conditions:
1. Controller issues an SLS command.
2. ONLINE switch on logic chassis maintenance panel
set to either OFFLINE position.
Lights when air flow is restricted enough to cause potential
overheating. If air flow is less than about 150 fpm past
either switch, indicator will light. One switch is located
next to the intake of the logic fan that cools +5V regulator.
The second switch is located at the intake of the power
supply fan that cools the power amplifier board.
Inhibits all write operations. Any subsequent WR T or WR T
TEST command will set State Violation (DSBI, Bit 2
3
).
3-6
DB37