HP 7936 Support Manual page 164

Troubleshooting and Diagnostics
7936 and 7937
Table 8-3. Servo System Test Connector AU3, Mnemonics (2 of 4)
PIN
NO.
12
13
14
15
16
17
18
19
20
21
22
23
8-42
MNEMONIC
PWM-L
DSRVPT
SMDT-H
AGND
ZDT
SLPES
DGND
+12UF
+5V
PES
AMFU-H
OPOS
SIGNAL
Pulse
Width
Modulation
Dedicated
Servo,
Positive,
Test
Sector
Mark
Detect
Analog Ground
Zero Detection
Slew
Position
Error
Signal
Digital
Ground
+12
Vdc,
Unfiltered
+5 Vdc,
Unfiltered
Position
Error
Signal
Amplifier
Unlatched
Offset
Position
Error
Signal
DESCRIPTION
Digital signal which shows the duty cycle
of the switching transistors.
Amplified signal from dedicated servo
head.
Asserted by the servo system when the
dedicated servo code sector mark pattern
is detected.
Analog Ground
Changes state when missing dibits in the
sector mark or guard band mark are
detected.
When track following, system switches to
slew PES to be less sensitive to changes in
position glitches.
Digital Ground
+12
Vdc power supply output, before PI
filters.
+5 Vdc power supply output, before PI
filters.
Either the dedicated or sampled position
signal, depending on whether the system
is presently in the dedicated or sampled
mode of operation.
Asserted when the actuator power amp is
disabled because of a fault.
PES signal plus any external DC offset
added to it. Also includes any transfer
function input.