Using the Sync Accessory Box
  • 23 Sep 2021
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Using the Sync Accessory Box

  • PDF

Your Kernel Flow system includes a Sync Accessory Box for collecting data from external devices during the recording of a Flow session. This might includes devices like heart rate monitors, a button/trigger, a force-plate, and so on. 

Image: Sync Accessory Box.You might also use the Sync Accessory Box to record task data generated from certain external devices. You do not need to use the Sync Accessory Box to record or synchronize data from Kernel's supplied tasks, or tasks created using Kernel's Task SDK (as long as your task-generating system is on the same local network as the Kernel Flow PC). In those cases, Kernel's software automatically synchronizes and record those data along with your Flow data.

Sync data collected through the Sync Accessory Box is included in the dataset for each recorded session, and may be accessed in downloaded reports and dataset files. To learn more, see Downloading datasets. 

Tasks involving the Sync Accessory Box include:


To setup the Sync Accessory Box:

  • Connect the Sync Accessory Box to the Kernel Flow PC using the supplied blue USB cable.
NOTE:
Do not use the red USB ports on the Kernel Flow PC.

View the Sync Accessory Box connections

The Sync Accessory Box has eight digital, and ten analog I/O ports that can all be used simultaneously. 

Image: Sync Accessory Box with various ports identified.

  • The eight standard analog ports contain a positive (+) and negative (-) connector (use either BNC or bare wire. To learn more, see below.) 
  • Depending on the type of device you are using, you may use just the +(for single-ended) or use both connectors (for differential). When both connectors are used, the value used is the difference between the positive and negative values (the negative is subtracted from the positive).
    NOTE:
    The negative analog ports are designed to support both Input and output (and so are labeled "IOn-"). Output will be supported in a subsequent release.
  • If you configure a digital port as an output, it will generate a 3.3v signal.
  • Each terminal block contains both digital and analog ports:

Image: Inset on terminal block of Sync Accessory Box with each pin identified.

(Manufacturer part number for Digital I/O mating housing: JST ZER-10V-S)


To connect an analog device:

Analog signals may be single ended (requiring one connector) or differential (requiring two connectors). When both connectors are used, the value used is the difference between the positive and negative values (the negative is subtracted from the positive).

  • Connect the output of your external device to a channel on the Sync Accessory Box. 
  • Use either BNC connectors or plug bare wires/pins into the terminal block for the corresponding input number (0-7). 
  • Be sure to ground any incoming (bare wire) signals.
    Image: partial view of Sync Accessory box with Analog ports called out.
Image: Alert icon.
When using a single-ended analog channel, do NOT attach wires to the (negative) BNC/pin for that channel. Doing so may damage your equipment. 
  • Use one of the two high-speed analog (HSA) inputs for sources that require a higher sampling rate such as EEG, EOG, etc.)
    Image; Partial view of Sync Accessory box with High Speed Analog inputs called out.
    • Inputs 0 - 7 are sampled at 1 kHz (BNC or bare wire)
    • Inputs HSA 0 and 1 are sampled at 10 kHz (BNC)
  • Analog input voltage (with programmable gain set to 1):
    • Single Ended: -5 to +5V
    • Differential: -5V to +5V
    • HSA (single ended): 0v - 2.5v
Image: Lightbulb icon.
When using bare-wire connectors, depress the wire-grip tab with a screwdriver while inserting the wire, then release the tab. The terminal block grabs the wire and hold it in place.

Depress the tab again to release the wire.


To connect a digital device:

  • Digital inputs can be plugged into the DIO slot of any of the terminal blocks on the Sync Accessory Box.
  • Be sure to always ground any incoming sources. 
  • Any signal between 0v and .9v will register as "low" (0), any signal 2.3v  to 5.3v will register as "high" (1).
    Signals between .9v and 2.3v may not trigger either state, and should not be used.

Image: Inset on terminal block of Sync Accessory Box with digital pins identified.

Image: Lightbulb icon.
When using bare-wire connectors, depress the wire-grip tab with a screwdriver while inserting the wire, then release the tab. The terminal block grabs the wire and hold it in place.

Depress the tab again to release the wire.
  • You can also connect digital sources using a ribbon cable, which can contain up to all eight digital inputs/outputs at once. This may be helpful for using the digital inputs for encoding a 1-byte symbol

Image: partial view of Sync Accessory Box with ribbon cable port called out.


To view the signals coming through the Sync Accessory Box:

  • In the Kernel Flow Desktop Application, click the Sync Box button.

Image: Kernel Flow Desktop Application with Sync Box button called out.

The Sync Accessory Box window opens. 

Image; Sync Box signal view with various controls called out.

The Analog tab displays the ten analog signals. The Digital tab displays the eight digital channels as well as a channel to display an encoded symbol.

Channels without signal display noise. 


To generate a digital signal:

In some cases you may want the Sync Accessory Box to output digital signals. You can set any digital channel to output 3.3v which can be used to power a recording device like a PPG monitor, or to provide a signal to another device. 

Image: Lightbulb icon.
You will be able to control this (and other Sync Accessory Box commands) via Python in a future release.

In the Kernel Flow Desktop Application, click the Sync Box button to open the Sync Accessory Box window.
The Sync Accessory Box window opens.

  1. In the Sync Accessory Box window, click the Controls button.
    The Digital Controls window opens.Image: Sync Box digital controls dialog.
  2. Select a channel (0-7) from the Channel field.
  3. Select the Output checkbox.
  4. Set the Digital Output State menu to 1.
    A constant 3.3 volt signal is generated to the DIO wire port in the terminal block for the channel you selected.
Image: Alert icon.
I/O Contention warning: Never connect an output signal from your external device to a port currently configured to generate an output signal. Doing so may damage your equipment.

Disconnecting the USB cable from the Sync Accessory Box re-configures all channels to be set as Inputs to minimize this risk. 


To use the digital channels to encode a signal:

In some cases, you may want to use all eight digital channels to be treated as a single byte of data to be encoded and recorded with your Flow data. 

  1. Connect pins to the DIO ports (or insert a cable to the Ribbon Cable port) on the Sync Accessory Box.
  2. Send a 1-byte signal from your data source encoded in binary where each of the digital channels represents a character in an 8-bit string:
  • Digital channel 0 is the right-most value: XXXXXXX_
  • Digital channel 7 is the left-most value:   _XXXXXXX

The resulting symbols are displayed in the Encoding Channel at the bottom of the Digital tab of the Sync Accessory Box window, and recorded as sync data in the Flow session. Image: Inset on Sync Accessory Box datastream window with Encoding Channel called out.