RoboteQ AX2550/2850 RS-232 Watchdog, Command Acknowledgement, Command Error, Watchdog time-out

Serial (RS-232) Controls and Operation

Command Acknowledgement

The AX2500/2850 will acknowledge commands in one of two ways:

For commands that cause a reply, such as a speed or amps queries, the reply to the query must be considered as the command acknowledgement.

For commands where no reply is expected, such as speed setting, the controller will issue a “plus” character (+) after every command as an acknowledgment.

Command Error

If a command or query has been received with errors or is wrong, the control will issue a “minus” character (-) to indicate the error.

If the controller issues the “-” character, it should be assumed that the command was lost and that it should be repeated.

Watchdog time-out

If the RS232 watchdog is enabled, the controller will stop the motors and issue a “W” character if it has not received a valid character from the PC or microcontroller within the past 1 seconds.

RS-232 Watchdog

For applications demanding the highest operating safety, the controller may be configured to automatically stop the motors (but otherwise remain fully active) if it fails to receive a character on its RS232 port for more than 1 seconds.

The controller will also send a “W” character every second to indicate to the microcom- puter that such a time-out condition has occurred.

The character does not need to be a specific command, but any valid ASCII code.

The RS232 watchdog is enabled or disabled depending on the value of the “Input Com- mand Mode” parameter.

The RS232 watchdog is automatically enabled when entering the RS232 mode from the RC or from the Analog modes (see “Entering RS232 from R/C or Analog mode” on page 91)

98 AX2500/2850 Motor Controller User’s Manual Version 1.7. February 1, 2005