tailieunhanh - McGraw-Hill- PDA Robotics - Using Your PDA to Control Your Robot 1 Part 4

Tham khảo tài liệu 'mcgraw-hill- pda robotics - using your pda to control your robot 1 part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | PDA Robotics from the time its LED finishes transmitting to the time its receiver diode is capable of receiving the remote station must wait 1 ms from receiving the last bit of a frame before beginning to transmit a new frame. The remote station performs this wait to honor the local transceiver s turnaround time. To honor the turnaround time of the remote transceiver the IrLAP protocol might sometimes specify to delay transmission of a packet. To do so the IrLAP protocol specifies the amount of time before a packet should be transmitted. The IrDA miniport driver must not transmit the packet before waiting the requested amount of time although the driver can wait longer if necessary. The IrLAP protocol specifies transmission delay time of a packet in the media-specific member of the packet s associated out-of-band OOB data block. IrLAP defines the format of the frames sent and received on the IR media. Each IrLAP frame consists of the following elements One or more beginning of frame BOF flags that mark the beginning of the frame. The size of the BOF member varies in length depending on the speed. An address A member that identifies the secondary connection address. The address member is 8 b. The address member specifies the address of a device that belongs to a particular IrDA miniport driver. This IrDA miniport driver transmits or receives the frame that contains this address through this device. A control C member that specifies the function of the particular frame. The control member is 8 b. An optional information I member that contains the information data. The information member is an integral number of octets. A frame check sequence FCS member that allows the receiving station to check the transmission accuracy of the frame. The FCS member is either 16 or 32 b depending on the speed. An end of frame EOF flag that signals the end of the frame. The size of the EOF member varies depending on the speed. The following example of an IrLAP frame shows the order of