Chapter 3
Theory of Operation
P/N 79000035_SM, Version 1.5 3 - 13 Focus 30/35 Service Manual
Block diagram
Fig. 3-11 Block diagram EDM
The functional parts/modules in the Distance meter unit are:
• Transmitter unit with Filter motor, Laser driver and 3RLaser.
• Transceiver board
• Step motor with Greywedge and Rhomboid prism (internal/external path)
• Reference fibre
• Receiver fibre
• Coax cable connect Laser drive board to Transceiver board
EDM offset
The Focus 30 instrument has the same offset when measuring in EDM mode (to reflector) and DR
mode (to DR target). This offset is measured in Offset determination in PASS.
Determination to 4x prism between 10 - 100m in minimum.
Verification/Validation to 1x prism between 10 - 100 meter, 1x DR target between 2,4 - 2,6m and 1x
DR target between 15 - 50m.
No short distance correction exists for the Distance meter unit.
Laser
driver
3R Laser
PLL-
frequency-
synthesizer
TCXO
14,985800
Mhz
AV-Photo
diode
Controler
USB
Interface
Transmitter unit
Grey
wedge
motor
Filter
motor
Receiver
fiber
High
voltage
supply
Coax cable
Transceiver board
Receiver
fiber
illumination