Synchronization

Overview
The Sonix systems allow for synchronization through BNC ports on the Ultrasonix PCI card installed on all systems. Depending on the system, the number of ports may vary. The BNC is a 5V TTL signal by nature, however some hardware modification may needed due to filters placed on the PCI to draw out the signal and lower the amplitude for signal connectivity to thermal printer devices.

BNC Layout
The Sonix RP has 2 BNC ports, one input and one output, and the SonixTOUCH Research has 4 BNC ports, two inputs and two outputs; the diagram below shows the configuration as installed within the system.



Output Pulses
By default the pulse on the output will look as below, an approximately 25ns 1V peak-to-peak pulse. This may be inadequate for triggering some devices, therefore the instructions below should be implemented to change the characteristics.



With PCI modification as described below, the following 3-5V peak-to-peak pulse can be achieved:



PCI Modification
By default, the Sonix systems have resistors on the PCI card to draw out the TTL pulse on the BNC output signals, and also reduce the amplitude in order to properly trigger thermal printers used often in clinical environments. To amplify the pulse for other device synchronization including triggering the SonixDAQ, the below modifications should be made:

SonixTOUCH Research:
 * Short R32 with 0 ohm resistor
 * Short XR41 with 0 ohm resistor
 * Remove XC32
 * Remove C52

Sonix RP:
 * Short R32 with 0 ohm resistor
 * Remove C52

Note that for the SonixTOUCH Research, the capacitors and resistors are located on the other side of the board.



Input Pulse

 * The input BNC should receive a 3-5 V TTL pulse, with a duration of 50-100 ns in order to trigger the system properly.
 * The hardware only looks at the rising edge of the signal.
 * Currently, the SonixTOUCH Research only supports 1 input signal (Input BNC #1), as no method for differentiation of signals has been implemented.