Analog Galvo

Device Compatibility

The analog galvo driver supports a wide variety of galvanometer scanners. Commonly used galvos are:

These models of galvo are often incorporated into a scanhead which is sold as a set of scanners and a controller tuned specifically to the scanhead.

The following scanheads are known to contain galvos as shown:

Hardware Config

Connect the galvo scanner or scanhead to the controller.

  • Choose a free analog output channel to connect to the controller position command input.

  • On the same DAQ board, choose a free analog input channel to connect to the controller position feedback output. (optional)

Software Config

From the Resource Configuration window, under the Devices tab click the add device “+” button.

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Select Scanner from the sidebar and then analog galvo and click “Add”. Assign it a name and click OK.

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In the window below, configure according to the installed galvos.

Definitions

Volts Per Optical Degree

The increment of control voltage required to deflect the beam 1 optical degree

Angular Range [Optical Degrees]

Peak-to-Peak angular range of each scanner in Optical Degrees

Parking Angle [Optical Degrees]

The angle that the galvos should be pointed when the system is “Parked”,

i.e. when not acquiring or pointing.

Slew Rate Limit [Volts/second]

The fastest rate at which the command voltage is permitted to change. This feature is only available on the vDAQ.

This may be set to prevent damage to galvonometer mirrors

Note

All angular values are in optical degrees - which is 2x the mechanical rotation angle of the scanner shaft. The total deflection is the incident angle + the reflected angle, which is 2x the mechanical rotation.

../../_images/laws-of-reflection.jpg

Note

Angular Ranges at Zoom=1

Zoom 1 is automatically defined as a square scan of the smaller of the two scanner angular ranges

Tip

It is permissible to use the full angular range of the larger of the two angular ranges, via the ROI/Stimulus Group Editor dialog