Siemens SIMATIC NET DP/AS-i Link 20E Manual page 74

Using the Command Interface
General Structure of the Send Buffer
The basic structure of the send buffer for commands is shown below. The bytes
only relevant with certain commands are shown on a gray background.
Byte
q+0
q+1
q+...
q = start address of the send buffer on the DP master
General Structure of the Receive Buffer
The basic structure of the response buffer is shown below. The bytes only relevant
with certain commands are shown on a gray background.
Byte
n+0
n+1
n+...
n = start address of the response buffer on the DP master
General Structure of the AS-i Slave Address
If an AS-i slave is addressed in a command or in a response, the address is
structured as shown below:
Bit 7
Where the S(elect) bit for selecting the slave type is specified as follows:
S S bit = 0
Standard AS-i slave or AS-i slave with extended addressing mode in address
area A
S S bit = 1
AS-i slave with extended addressing mode in address area B
74
Command number
Response data
Response data
Response data
Bit 6 Bit 5 Bit 4
S bit
Meaning
Job data
Job data
Meaning
Slave address
DP/AS-Interface Link 20E
C79000-G8976-C235−01
Bit 0
Release 08/2008