Delta ASDA-B2-F Series User Manual

Contents

Communications ASDA-B2-F8-4 September, 201588.3 MODBUS Communication ProtocolThere are two modes of MODBUS network communication: ASCII (American Standard Code forInformation Interchange) and RTU (Remote Terminal Unit). Users could set the desiredcommunication mode via P3-02. Apart from these two communication modes, this servo drivealso supports functions of accessing more than one data (03H), writing one character (06H) andwriting multiple characters (10H). Please refer to the following descriptions.Code DescriptionASCII Mode:In ASCII mode, data are transmitted in ASCII (American Standard Code for InformationInterchange) format. When transmitting data 64H between two stations (Master and Slave), themaster will send 36H to represent ‟6” and 34H to represent “4”.ASCII code for digits 0 to 9 and characters A to F are as follows:Character ‘0’ ‘1’ ‘2’ ‘3’ ‘4’ ‘5’ ‘6’ ‘7’ASCII Code 30H 31H 32H 33H 34H 35H 36H 37HCharacter ‘8’ ‘9’ ‘A’ ‘B’ ‘C’ ‘D’ ‘E’ ‘F’ASCII Code 38H 39H 41H 42H 43H 44H 45H 46HRTU Mode:Every 8-bit data is constituted by two 4-bit characters (hexadecimal). If data 64H is transmittedbetween two stations, it will be transmitted directly, which is more efficient than ASCII mode.Character StructureCharacters will be encoded into the following framing and transmitted in serial. The checkingmethod of different bit is as the following.10-bit character frame (for 7-bit character)7N2 StartbitStopbitStopbit0 1 2 3 4 5 67-data bits10-bit character frameL H H7E1 StartbitEvenParityStopbit0 1 2 3 4 5 67-data bits10-bit character frameL H7O1 StartbitOddParityStopbit0 1 2 3 4 5 67-data bits10-bit character frameL H