ultrak498.py is a python script for reading timing data from an Ultrak 498 printing stopwatch.

To upload a race (or all races) from the Ultrak 498:

• Ensure the upper left yellow switch is in the OFF/UPLOAD position.
• Press MODE till Upload All is displayed.
• Press LAP/RESET/SELECT to select the race number; skip to the next step to upload all stored races.
• Press S/S PRINT to start the Upload.

The data port is located on the right side of the Ultrax 498 and is labeled PC. The data port uses an RJ11 connector. When looking at the device, the pins are labeled:

1 2 3 4

The pinout is:

• 1: GRND (Connect to ground of level converter)
• 2: TX (Connect to RX of level converter)
• 3: ? (No Connect)
• 4: ? (No Connect)

Output is 4800 N81 TTL serial, no flow control. A level converter is needed to connect to a PC serial port. Alternatively, a TTL Serial to USB converter such as FTDI Basic Break 5V from Sparkfun can be used to read data from the device. See the Usage section for instructions on initiating a download.

Under Linux, the following two commands will display the raw output:

% stty -F /dev/ttyUSB0 4800 raw
% od -tx1 --width=5 /dev/ttyUSB0

The Ultrak 498 transmits fixed width fields in packed binary coded decimal. Each field is five bytes wide. Each byte represents a decimal value from 0 to 99 and is in little endian order (first nibble/digit is the ones, second nibble/digit is the tens).

The first byte of each field indicates the field type. The remaining bytes represent the data for that field type. There are six known field types.

• 00: Race Header
• 10: Lap Time
• 20: Absolute Time
• 30: Unknown
• 40: Unknown
• 50: Race Stop

This field represents the start of a race. A race starts when the timer reads zero, the timer is not running, and the start/stop button is pressed.

• 0: Type
• 1: Year
• 2: Month
• 3: Day
• 4: Race ID

The date must be set within the timer for the year/month/day to be correct. If no date has been set these fields are set to 10/1/1 respectively.

This field represents the time elapsed since the last lap (the previous time the yellow lap button was pressed).

• 0: Type
• 1: Minutes
• 2: Seconds
• 3: Hundreths
• 4: Lap/Place

NOTE: Since the maximum value stored by a two digit binary coded decimal is 99, therefore, the maximum value for lap/place is 99. The format can't represent values over 100. Thus, the lap/place rolls over to 0 each time a multiple of 100 is reached.

This field represents the absolute time since the start of the race (the previous time the black start/stop button was pressed).

• 0: Type
• 1: Minutes
• 2: Seconds
• 3: Hundreths
• 4: Lap/Place

NOTE: See note above in regards to lap/place.

• 0: Type
• 1: Unknown
• 2: Unknown
• 3: Unknown
• 4: Laps

• 0: Type
• 1: Unknown
• 2: Unknown
• 3: Unknown
• 4: Laps

This field represents the time the race ends. A race ends when the start/stop button is pressed while the timer is running.

• 0: Type
• 1: Minutes
• 2: Seconds
• 3: Hundreths
• 4: Total Laps/Places