Communication is established via a virtual serial port provided by a built-in USB-serial-converter (FTDI FT232R), with 19200BAUD 8N1. Make sure to have the latest FTDI drivers installed.

PULL Protocol

Your software always initiates any communication by calling a command. The USB Timing Box will immediately respond and then wait for the next call. There is one exception: prewarns. If you enable prewarns, data is pushed without notice (but only if no other command is processing/pending).

The USB Timing Box only processes one command at a time. If you call a command, you must always wait for the response to finish, before sending the next command.

DTR-Line Reset

It is critical that you actively control the DTR-Line (Data-Terminal-Ready) and set it to LOW/false as default setting at all times. If the DTR line is HIGH/true for more than 500msec, the USB Timing Box will do a hard reset! This is intended behavior and allows a host application to reset the box to a known default state.

Hint: Some serial libraries will require you to specifically switch on DTR-Line handling when opening the connection.

RACE RESULT recommends using a terminal tool like HTerm to try and test the connection by manual commands. Make sure your tool of choice defaults DTR to low. PuTTY for example does not!

Known Issue "NON GENUINE DEVICE"

If you or your customer ever encounter a "NON GENUINE DEVICE" message sent from the USB Timing Box, please be assured that RACE RESULT does only source genuine devices. This problem is caused by an error in the FTDI driver. Please follow the steps here.