MODBUS RTU SLAVE(CODESYS_SYSCOMLIB)

CODESYS 2.3 Modbus RTU Slave 实现(Syscomlib libaray) PLC PRG(MAIN PROGRAM) SM320_STATUS:=%IX4.0; IF NOT sm320_status THEN CASE i_state OF 0:CS.dwBaudRate:=19200; cs.byParity:=2; cs.byStopBits:=1; cs.cByteSize:=8; cs.dwBufferSize:=0; COM_OPEN:=SysComOpen(COM_PORT_EXT_RS4XX + COM_PORT_EXT_ADDR0+ COM_PORT_EXT_UPPER ); IF COM_OPEN <> INV ALID_HANDLE AND COM_OPEN <> 0 THEN (* For the module SM230/A *) SysComSetMode(COM_OPEN, COM_MODE_RS485_ENABLE); (* Configure the COM-Port, Baudrate, Port, ... *) SettingsOK := SysComSetSettingsEx(COM_OPEN,ADR(cs)); IF SettingsOK THEN i_state:=10; ELSE i_state:=99; END_IF; END_IF; 10: (*read data*) IF COM_OPEN <> INV ALID_HANDLE AND COM_OPEN <> 0 THEN read_act:=SysComRead(com_open,ADR(input_byte),SIZEOF(input_byte),0); input_byte1:=input_byte; IF read_act<>INV ALID_HANDLE THEN (* ton1(in:=flag_rec,pt:=t#5ms); IF ton1.Q THEN*) frame_process(); IF send_do THEN i_State := 20; ELSE i_state:=15; (* END_IF;*) END_IF; ELSE i_state:=99; END_IF; END_IF; 15: i_State := 10; 20: (*write data*) IF COM_OPEN <> INV ALID_HANDLE AND COM_OPEN <> 0 AND send_do=TRUE THEN read_act1:=SysComWrite(COM_OPEN, ADR(output_byte),write_len,0); i_State := 10; send_do:=FALSE; FOR i:=1 TO 10 DO input_byte[1]:=0; END_FOR; ELSE i_state:=99; END_IF; 99:SysComClose(com_open); com_open := 0; i_State := 0; END_CASE; END_IF; (*IF crc_cal THEN crc_checka( lengthcrc:= length_checka, inbyte:=test_crc, CRC16CVT=>crc_outa ); END_IF;*) Frame process: (sub program) IF (( input_byte1[1]<16#FF) AND( input_byte1[1]>0)) AND( (input_byte1[2]=01) OR (input_byte1[2]=05) OR( input_byte1[2]=03 ) OR( input_byte1[2]=6 )OR(input_byte1[2]=16)) THEN (*CRC16 check action *) IF input_byte1[2]=03 OR input_byte1[2]=06 THEN length_check:=6; END_IF; IF input_byte1[2]=16 THEN length_check:=7+input_byte1[7]; END_IF; crc_check( lengthcrc:= length_check, inbyte:=input_byte1, CRC16CVT=>crc_out ); crc_temp:=SHL(BYTE_TO_WORD(input_byte1[length_check+1] ),8) OR BYTE_TO_WORD(input_byte1[length_check+2] ); (* CRC16 check OK then the process is going on ,judge the function code to response *) IF ( crc_out = crc_temp<>0) AND (send_do =FALSE )THEN CASE input_byte1[2] OF 03: output_byte[1]:= input_byte1[1]; output_byte[2]:=03; address_temp:=SHL(BYTE_TO_INT(input_byte1[3]),8) + ( BYTE_TO_INT(input_byte1[4])); length_temp:=SHL(BYTE_TO_INT(input_byte1[5]),8) +(BYTE_TO_INT(input_byte1[6])); output_byte[3]:=INT_TO_BYTE((length_temp)*2); FOR move_to_send:=address_temp TO address_temp+(length_temp)*2 DO output_byte[4+move_to_send-address_temp]:=mw_area[move_to_send+address_temp+1]; END_FOR; length_check1:=3+(length_temp)*2; crc_check( lengthcrc:= length_check1, inbyte:=output_byte, CRC16CVT=>crc_out1 ); output_byte[4+(length_temp)*2]:= WORD_TO_BYTE(SHR((crc_out1 AND 16#FF00 ),8)); output_byte[5+(length_temp)*2]:= WORD_TO_BYTE(crc_out1 AND 16#FF ); write_len:= 5+(length_temp)*2;send_do:=TRUE; 16: FOR move_to_send:=1 TO 6 DO output_byte[move_to_send]:=input_byte1[move_to_send]; END_FOR; address_temp:=SHL(BYTE_TO_INT(input_byte1[3]),8)+ BYTE_TO_INT(input_byte1[4]); length_temp:=SHL(BYTE_TO_INT(input_byte1[5]),8)+ BYTE_TO_INT(input_byte1[6]); FOR move_to_send:=address_temp TO address_temp+(length_temp)*2-1 DO mw_area[move_to_send+address_temp+1]:=input_byte1[8+move_to_send-address_temp]; END_FOR; length_check1:=6; crc_check( lengthcrc:= length_check1, inbyte:=output_byte, CRC16CVT=>crc_out1 ); output_byte[7]:= WORD_TO_BYTE(SHR((crc_out1 AND 16#FF00 ),8)); output_byte[8]:= WORD_TO_BYTE(crc_out1 AND 16#FF ); write_len:= 8;send_do:=TRUE; 06: FOR move_to_send:=1 TO 8 DO output_byte[move_to_send]:=input_byte1[move_to_send]; END_FOR; address_temp:=SHL(BYTE_TO_INT(input_byte1[3]),8)+ BYTE_TO_INT(input_byte1[4]); mw_area[address_temp*2+1]:=input_byte1[5];mw_area[address_temp*2+2]:=input_byte1[6]; write_len:= 8;send_do:=TRUE; END_CASE; END_IF; END_IF; Crc_check: (Function block) (*CRC16 check *) crctmp := 16#FFFF; FOR crci:= 0 TO (lengthcrc - 1) DO crctmp:= crctmp XOR inbyte[crci]; FOR crcj:= 1 TO 8 DO tempcrc:=1 AND crctmp; crctmp :=SHR( crctmp ,1); IF tempcrc = 1 THEN crctmp:= crctmp XOR 16#A001 ; END_IF; END_FOR; END_FOR; lcrc := SHL((crctmp AND 16#FF) , 8); hcrc:=SHR( (crctmp AND 16#FF00) , 8); CRC16CVT:= lcrc OR hcrc;