Table of Contents

Property NumberOfUsbFramesToSync

Namespace
ComfileTech.Cfnet.Cfheader
Assembly
ComfileTech.Cfnet.Cfheader.dll

NumberOfUsbFramesToSync

The number of USB Start of Frame (SoF) interrupts the CFHEADER module will receive before writing to and reading from the connected IO modules via I²C, effectively synchronizing the I²C communication with the USB host.

public sbyte NumberOfUsbFramesToSync { get; set; }

Property Value

sbyte

Remarks

  • -1 - The CFHEADER will write to and read from the connected IO modules via I²C immediately after receiving a USB OUT transfer from the host. The I²C communication will be not be performed unless a USB OUT transfer is received from the USB host. This effectively makes the timing of the I²C communication dependent on the ability of the host application and host operating system to send USB OUT transfers to the CFHEADER module deterministically and in real time.
  • 0 - The CFHEADER will write to and read from the connected IO modules via I²C immediately after the last I²C iteration, effectively ignoring the USB Start of Frame (SoF) interrupt. The I²C communication will be performed regardless of whether the CFHEADER module has received a USB OUT transfer from the USB host, even if the CFHEADER is not connected to a USB host via a USB cable. This effectively removes any synchronization of I²C communication with the USB host.
  • 1 - The default. The CFHEADER module will write to and read from the connected IO modules via I²C on every USB Start of Frame (SoF) interrupt, effectively every millisecond. The I²C communication will be performed regardless of whether the CFHEADER module has received a USB OUT transfer from the USB host. If the CFHEADER is not connected to a USB host via a USB cable, it will not receive SoF interrupts, so will, therefore, not perform any I²C communication.
  • 2 - The CFHEADER module will write to and read from the connected IO modules via I²C on every 2 USB Start of Frame (SoF) interrupts, effectively every 2 milliseconds. The I²C communication will be performed regardless of whether the CFHEADER module has received a USB OUT transfer from the USB host. If the CFHEADER is not connected to a USB host via a USB cable, it will not receive SoF interrupts, so will, therefore, not perform any I²C communication.
  • 3 - The CFHEADER module will write to and read from the connected IO modules via I²C on every 3 USB Start of Frame (SoF) interrupts, effectively every 3 milliseconds. The I²C communication will be performed regardless of whether the CFHEADER module has received a USB OUT transfer from the USB host. If the CFHEADER is not connected to a USB host via a USB cable, it will not receive SoF interrupts, so will, therefore, not perform any I²C communication.
  • etc...