Writing Application Code

Protocol Characteristics

• All commands are initiated by the PC (client)
• All replies are received from the stepper-controller target (server)
• Uses variable-length ASCII console-compatible commands, data, and replies
• Command fields are separated by an ASCII space (0x20)
• Multiple commands are allowed on a command line
• Command lines are terminated with an ASCII CR (0x0D)
• Commands are reverse Polish, or postfix notation (data precedes operation)
• Numerical data values are ASCII decimal (default number base) integers
• Valid values for numerical data are +/-32767
• Commands are case sensitive
• The target always echoes the command line before execution
• A successfully interpreted command line is followed by any reply data, followed by the "ok" prompt

  \r\nok (0x0d 0x0a 0x6f 0x6b 0x20) 

• An unsuccessfully interpreted command line is followed by the unknown token, followed by

  ?\r\n (0x3f 0x0d 0x0a) 

• Motion Commands in blocking mode send the "ok" prompt when the motion, including settling delay, is complete
• Only two StepperII console commands return data
  • pos returns the current position of the active axis in ASCII decimal units
  • state returns the current run state of the active axis (see CRunProfile) in ASCII decimal