Leica M500 N Service Manual page 14

Description
08/2007 Gahe
Processor
A watch-dog is integrated in the H8-processor. It observes the running of the main program. Diagnosis LED's might
help with trouble shooting, refer to
The PWM outputs are driven with the optimum frequency of 20kHz (above the noise-limit, below magnetization
problems).
Motor driver
The zoom- , focus and Iris motors are powered with a +24V PWM-signal. A one-chip controller receives enable-,
direction- and the puls-rate-information from the processor and drives the motors accordingly. All motors have an
encoder mounted directly on the motor axis. The encoder pulses are received by a counter, where the A/B-signals
(direction) are decoded and the actual position transferred further to the processor. A current limitation for the motors
becomes active for current > 0,3A.
Range
The initializing of the microscope sets the lower limit to 1000 encoder-pulses. The actual upper limit is determine with
counting the encoder-pulses (constants are stored for these values; deviations of the displayed values are possible
due to mechanical tolerances).
F o c u s 2 0 7 m m
Z o o m O U T
8 0 0 1 0 0 0
RS232
A serial interface for service purposes is available. It is directly wired to the Optics-carrier processor - and has
therefore other signal level for TxD than RS232 standard.
Recognition of optics carrier type
Since the increase of the working distance from 407 to 470mm (M500 N to M520) a recognition of the optics carrier
type is required. A bridge on P6 (pin1-pin4) is installed in optics carrier M520 and M525. A status command, requested
from control unit at system start , delivers the information if the bridge is installed or not.
Additional functionality on motorcontroller for M525
The AutoIrsis function in the M525 required an additional motor and a redesign of the motorcontroller. All existing
functions were taken over (backwards compatible) and additional circuits for Iris motor drive and Iris control were
integrated. The movement of the Iris motor is completely handled by the motorcontroller, no direct access via the CAN
bus is possible.
Software history
Software Release date
version
1.4 02/98
2.3 04/99
2.4 05/01
4.4 xx/06
Software compatibility in respect of control unit see
chapter 4 – fault finding / diagnosis
U P D O W N
D O W N U P
w o rkin g ra n g e
HW motorcontroller
10 661 250
-"-
-"-
10 714 356
chapter inspection / step
Service manual M500 N, M520, M525
1-10
LED's.
F o c u s 4 0 7 m m
Z o o m IN
u p p e r lim it
ra n g e .ds 4
Compatibility
M500 N
M500 N
M500 N, M520
M500 N, M520, M525
2.13.
Doc Code 10 665 751
or 470mm (M520, M525)
Zoom: 28500
Focus: 23800
Remark