The TCommLSCheckStatus structure

 // CommLSCheckStatus
 TCommLSCheckStatus     struct
  Result                sbyte  // The function call result.
  Port          byte   // The port to which the I2C device is connected.
  BytesReady    byte   // The number of bytes ready to read from the specified port.
 TCommLSCheckStatus     ends

Possible Result values include ERR_COMM_BUS_ERR, ERR_COMM_CHAN_INVALID, STAT_COMM_PENDING, ERR_COMM_CHAN_NOT_READY, and NO_ERR.