台达可编程逻辑控制器plc 通信协议.doc

DELTA DVP Series PLC
COMMUNICATION PROTOCOL VER
Communication Interface: RS-232C
Communication Protocol ASCII mode, 9600(Baud rate), EVEN(Parity), 1(Start bit),1(Stop bit)
Communication Data Frame
STX
Start character ‘:’(3AH)
ADR 1
Communication address:
ADR 0
8-bit address consists of 2 ASCII codes
CMD 1
Command code:
CMD 0
8-mand consists of 2 ASCII codes
DATA(0)
Contents of data:
DATA(1)
n´8-bit data consist of 2n ASCII codes.
……….
n£37, maximum of 74 ASCII codes
DATA(n-1)
LRC CHK 1
LRC check sum:
LRC CHK 0
8-bit check sum consists of 2 ASCII codes
END 1
End character:
END 0
END 1 = CR(0DH),END 0 = LF(0AH)
munication Address)
munication addresses are in the range of 0…31. Communication address equals to 0 means broadcast to all PLC, the PLC will reply normal message to the master device.
For example, communication to PLC with address 16 decimal:
(ADR 1, ADR 0)=’1’,’0’ð’1’=31H, ‘0’= 30H
CMD (Command code) and DATA (data characters)
The format of data characters depends on mand code. For example, reading continuous 8 words form starting device address 0614H of PLC with address 01H.
Field Name
Example (Hex)
Heading
3A
Slave Address
01
Command code
03
Starting Address Hi
06
Starting Address Lo
14
Number of Points Hi
00
Number of Points Lo
08
Error Check ( LRC )
DA
Number of Points(max)
= 18(for 16 bit register)
= 9(for 32 bit register)
Example:Reading Coils T20~T27 from slave device 01
PC→PLC
“:01 03 06 14 00 08 DA CR LF”
PLC→PC
“:01 03 10 00 01 00 02 00 03 00 04 00 05 00 06 00 07 00 08 B8 CR LF”
Field Name
Example (Hex)
Slave Address
01
Command code
03
Bytes Count
10
Data Hi(T20)
00
Data Lo(T20)
01
Data Hi(T21)
00
Data Lo(T21)
02
Data Hi(T22)
00
Data Lo(T22)
03
Data Hi(T23)
00
Data Lo(T23)
04
Data Hi(T24)
00
Data Lo(T24)
05
Data Hi(T25)
00
Data Lo(T25)
06
Data Hi(T26)
00
Data Lo(T26)
07
Data Hi(T27)
00
Data Lo(T27)
08
Error Check(LRC)
C8
LRC CHK(ch