文档介绍:台达PLC通讯协议原文
1、通讯协议ASCII模式,9600,7,e,1
2、通讯资料格式:
STX
头码‘:’(3AH)
ADR1
通讯地址:
8-bit位址包含了2个ASCII码
ADR0
CMD1
命令码:
8-tarting Address Hi
06
Starting Address Lo
14
Number of Points Hi
00
Number of Points Lo
25
Error Check (LRC)
BF
Number of Points(max)= 255 = 0x00FF
例:从从动装置01读取线圈T20-T56
PC→PLC “:01 01 06 14 00 25 BF CR LF”
PLC→PC “:01 01 05 CD 6B B2 0E 1B E6 CR LF”
Field Name
Contents
Slave Address
01
Function
01
Bytes Count
05
Data (Coils T27…T20)
CD
Data (Coils T35…T38)
6B
Data (Coils T43…T36)
B2
Data (Coils T51…T44)
0E
Data (Coils T56…T52)
1B
Error Check (LRC)
E6
Function Code :02,Read Input Status
Field Name
Example (Hex)
Heading
3A
Slave Address
01
Function
02
Starting Address Hi
05
Starting Address Lo
14
Number of Points Hi
00
Number of Points Lo
25
Error Check (LRC)
BF
例:从从动装置01读取接点Y024-Y070
PC→PLC “:01 02 05 14 00 25 BF CR LF”
PLC→PC “:01 02 05 CD 6B B2 0E 1B E5 CR LF”
Field Name
Contents
Slave Address
01
Function
02
Bytes Count
05
Data (Coils Y033…Y024)
CD
Data (Coils Y043…Y034)
6B
Data (Coils Y053…Y044)
B2
Data (Coils Y063…Y054)
0E
Data (Coils Y070…Y064)
1B
Error Check (LRC)
E5
Function Code :03,Read Holding Registet
Field Name
Example (Hex)
Heading
3A
Slave Address
01
Function
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)
例:从从动装置01读取线圈T20-T27
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
Contents
Slave Address
01
Function
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)