Signal Intensities

When taking measurements, the signal intensity is an important factor. Automatic gain control (auto-gain) can be used to automatically set pulse_length and intensity to receive a good signal intensity.

Defining an Auto-Gain

First step is to setup an auto-gain control in a protocol. The following parameters have to be defined:

Parameter	Type	Description
index	int	Select an index number to access the gain settings in the protocol (0-9)
led	int	Select the LED used for auto-gain
detector	int	Select the detector used for auto-gain
pulse length	int	Define the duration of the pulse (in µs)
target intensity	int	Define the target intensity (0-65,535)

"autogain": [
    [ <index>, <led>, <detector>, <pulse length>, <target intensity> ]
]

TIP

Find the protocol command documentation here.

Defining Multiple Auto-Gains

Multiple auto-gains can be used inside a protocol, depending on the number of lights and detector combinations used. Up to 10 auto-gain settings can be defined.

  {
    "autogain": [
      [ 1, 3, 1, 30, 3000 ],
      [ 2, 4, 1, 30, 5000 ],
      ...
    ]
}

Note

Always make sure, that the index used for each gain is unique. There is no error checking on the Instrument side.

Applying Auto-Gain Values

When autogain is defined in a protocol, for each auto-gain the variables auto_duration<index> and auto_bright<index> will be return and can be used to set the pulse_length and pulsed_lights_brightness.

To access the output for the autogain with the index 2, the variables would be auto_duration2 and auto_bright2.

"pulse_length": [
    [ "auto_duration<index>" ], ...
]

"pulsed_lights_brightness": [
    [ "auto_bright<index>" ], ...
]

Code Example

  {
    "autogain": [
      [ 1, 3, 1, 30, 3000 ]
    ],
    "pulse_length": [
      [ "auto_duration1" ]
    ],
    "pulsed_lights": [
      [ 3 ]
    ],
    "pulsed_lights_brightness": [
      [ "auto_bright1" ]
    ],
    "detectors": [
      [ 1 ]
    ]
}