Most Watson Industries digital sensors have settings that are saved in memory. These settings include things like data channels, and baud rate that users might find the need to change from time to time. In order to access the menu system to change these settings, the senor needs to be in Command Mode. There are a series of steps that need to be performed to put the sensor into this special mode.

  1. Connect the unit to a DC power source that is off.
  2. The viewing computer needs a valid bi-directional RS-232 serial port. Connect the serial port of the Watson sensor to the computer’s serial port.
  3. Open a terminal program (such as HyperTerminal) to interface with the unit. The default baud rate of the unit is 9600 baud. Make sure the computer’s serial port is open.
  4. Power-on the unit. A startup message will be transmitted by the unit and will appear in the terminal window unless it has been suppressed.
  5. During initialization, hit the space bar twice within close succession.

    Note: The sensor initialization time begins after the startup message is transmitted. Typically, this time period lasts 5 seconds, but could be as long as 127 seconds depending on your sensor.

  6. Wait until after initialization is finished. At this point, command mode will be activated and the unit will accept keyboard commands.

    Note: Most Watson sensors have initialization times that are shorter than 30 sec. Any extra keystrokes (other than two spacebars) sent during initialization will deactivate command mode.

It can often take a few attempts to get the hang of step 5. Repeat steps 4-6 until successful.