Signal Conditioning Controls

Note

The Signal Conditioning Controls window is available in ScanImage

The Signal Conditioning controls is helpful for a variety of uses, including:

• Acquisition Gating for low rep rate Lasers

• Photon Counting

• Duplicating Displays on virtual channels

• Setting a low pass filter on the PMT signal (medium speed vDAQ only)

Sample Clock Settings (Blue)

Clock Source	Select either the Internal Clock rate of 125MHz, or an external clock Note The high speed vDAQ using an external clock must receive a clock with a frequency 62.5 MHz - 84.375 MHz
Input Clock rate	The clock rate used to determine the Sample Rate. This is automatically detected. If the detected frequency is wrong for an externally supplied clock, then check the setup for time correlated photon counting
Clock Multiplier	This is essentially the number of samples collected for every rising edge of the Input Clock Rate (MHz) Note At present, the only supported clock multiplier for the high speed vDAQ is 32.
Sample Rate (MHz)	This is the Input Clock rate multiplied by the Sample Rate. Note ensure this is within the range of sampling rates supported by your DAQ. DAQ Frequency Range vDAQ 62.5 MHz - 125 MHz vDAQ-HS 2.0 GHz - 2.7 GHz

Physical Channel Settings (Green)

This essentially duplicates the role of the Channels window. As virtual channels are added, their settings can also be configured.

Tip

If using the medium speed vDAQ, you can specify the cutoff for a low pass filter in the right most column.

Physical Channel	The channel for which the row’s settings should be applied
Range	The input voltage range that should be mapped to the ADC counts range of the DAQ
Invert	Whether higher ADC counts should be represented as brighter or darker pixels (checked inverts such that high counts are dark).
Subtract Offset	Whether or not to subtract the dark current offset.
Offset Value	The amount in ADC counts to subtract when subtract offset is enabled.
LP Filter (medium speed vDAQ only)	Whether or not to enable the anti-aliasing low pass filter
Cutoff	The cutoff frequency of the anti-aliasing low pass filter

Laser Trigger Settings (Yellow)

Input Terminal	The terminal from which the the laser trigger is received. For the HS vDAQ, this is only the CLK_IN (IN) port. On the MS vDAQ, this can be any DI or DIO port.
Trigger Phase Adjust	Compensate for any delay between the signal and triggering with this. You can adjust a maximum of the Clock Multiplier (samples per laser pulse) before looping.
Detected Freq (MHz)	This is a readout of the detected frequency. It will update after acquiring PMT samples from the Signal Scope panel (highlighted purple).
Period (Ticks)	This is number of times a sample is taken at the Detected Frequency (i.e. the Clock Multiplier, or the samples per laser pulse). Note This is relevant if synchronizing to an external sample clock.

Virtual Channel Settings (Orange)

For the medium speed vDAQ:

Channels	ScanImage Display/Save Channels
Source	Analog Inputs assigned to a ScanImage Display/Save Channel
Threshold (checkbox)	Whether or not to apply the threshold specified in Threshold (editable text)
Threshold (editable text)	The quantity in ADC counts to compare the signal to to decide whether to write the pixel value to the image. Values less than the threshold are not written.
Binarize	If true, pixel values are written as either a 1 (above the threshold) or 0 (below the threshold)
Laser Filter	If true, the temporal window specified in the next column will be applied to mask which samples are binned for averaging
Window	the temporal window to mask which samples are binned for averaging
Delete	Can delete virtual channels by clicking the X

For the high speed vDAQ:

Channels	ScanImage Display/Save Channels
Source	Analog Inputs assigned to virtual channel
Mode	Decide between analog (photo integration) or photon counting pipelines
Average	Whether or not to average (rather than add) samples before binning
Laser Filter	If true, the temporal window specified in the next column will be applied to mask which samples are binned for averaging
Window	the temporal window to mask which samples are binned for averaging
Delete	Can delete virtual channels by clicking the X

Signal Scope (Red)

Physical Channel	The port on the vDAQ PCIe card to sample from
Capture Length	The number of samples to collect
Start Continuous	Start monitoring samples on the PMT Signal graph
Grab Single	Grab a single capture length of samples and display on the PMT Signal graph.