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2.2.8.7 APL Lighting Board 
The APL lighting board is used to indicate the manual APL knob. 
 
 
Installation position of the APL lighting board 
 
APL lighting board 
2.2.8.8 External I/O Interface Board 
The external I/O interface board provides external ports, including four USB ports, two network 
ports, and one DB9 port (for calibration and device interconnection). No software is configured 
for this board. 
The APL lighting board 
is installed here.