Appendix A 1. It is suggested that the two ends of the bus should be connected with one resistor of 120Ω respectively. 2. To ensure the communication quality , the double shielded and twisted-pair cable is recommended （ 20AWG ） . 3. When the internal voltages of two devices are different, make SG （ Signal Ground ） of the two device connected with each other to balance their SG voltages and make the communication more stable. ASCII Mode 1. Communication data structure The corresponding relation between hexadecimal character and ASCII code: 2. ADR (Communication address) The valid range of communication address: 0 ～ 254. Communication address:
0 means the broadcast message is sent to all slaves and the slaves which have received the message will not make any response. If communication address is not 0, slaves will respond to master after receiving the message normally. For instance, ASCII codes for the communication address of 16 are denoted below. Decimal 16 is equal to hexadecimal 10. （ ADR 1, ADR 0 ） =’10’ ， ‘1’=31H, ‘0’ = 30H 3. Function code and data A-6 DVP-MC operating manual Field name Components Explanation Start character STX Start character “:”, the corresponding ASCII code: 0x3A Communication address ADR 1 Communication address consists of two ASCII codes.
ADR 0 Function code CMD 1 Function code consists of two ASCII codes. CMD 0 Data DATA （0） Data content consists of 2n ASCII codes, n≤205. DATA （1） ………. DATA （n-1） LRC Check LRC CHK 1 LRC check consists of two ASCII codes. LRC CHK 0 End character END1 End character consists of two ASCII codes. END1 = CR （0x0D）， END0 = LF （0x0A） END0 Hexadecimal character “0“ “1“ “2“ “3“ “4“ “5“ “6“ “7“ ASCII code 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x37 Hexadecimal character “8“ “9“ “A“ “B“ “C“ “D“ “E“ “F“ ASCII code 0x38 0x39 0x41 0x42 0x43 0x44 0x45 0x46