The following diagram follows the entire path of the Scanning Interface Unit (SIU) v2.2 horizontal scan circuit.

printing this page: Set view to landscape and print at 40%.

Notes:

• Scanning Interface Rev 2.2 is printed on the card inside the SIU.
• SEII Rear Panel Connector is that of the computer card.
• Scanning I/O B is an SIU rear panel connector.
• The circuit shown is inside the SIU.
• The SEII generates a ±3 volt fast ramp into the SIU.
• The op-amp circuits add gain and offset.
• The ramp exits at Scanning I/O B at pin 3 and goes to the microscope.
• Scanning I/O B can also receive a ramp at pin 11 for switching needs.
• The relay switches both the signal and ground.