Newport FSM-300, User Manual

Page: 34 / 42

34 System Components
optimizing their application. As a practical guide, a well-defined, smooth
sinewave input will generate the best output results.
Self-heating of the mirror drive coils is proportional to command signal
amplitude and to the square of frequency. Consult
Figure 5
in the specifica-
tion section of this manual for the Safe Operating Area before driving your
FSM system near its frequency versus amplitude maxima. The gain and
phase response as a function of frequency for typical FSM systems are shown
in
Figures 3 & 4
.
6.4 Position Outputs
If confirmation of mirror position is desired, the position angle sensors can
be monitored at the Position Output pins (pins 18 and 20) of the 25-pin
INTERFACE I/O connector on the front panel. A full-scale deflection of
±1.5º on either axis corresponds to a ±10 V output swing. Zero volts output
corresponds to a powered-on null, or 0º.
6.5 Fault Indication
Two LED fault indicator lights on the front panel, labeled CURR and TEMP,
are used to indicate overheating of the drive coils, as measured separately by
thermistors for the X and Y axes.
•
The yellow CURR
warning indicator light comes when the temperature
of the drive coils has reached a warning threshold as a result of applying
too high an RMS drive current. In the event that the yellow light comes
on during continuous system operation, decrease the amplitude and/or
frequency of the drive signal.
•
The red TEMP
shut-off light comes on when thermistors have reached
the shut-off temperature threshold, above which the over-temperature
condition would damage the coils. While the red light is on, the mirror
will be in the unpowered state. Upon cooling of the coils, the red light
will go off, and the system will automatically resume normal operation.
In the event that the red warning light comes on during continuous system
operation, decrease the amplitude and/or frequency of the drive signal.
Also check for possible inverse polarity of an External Feedback signal.