Command Interface Of The Dp/As-Interface Link 20E - Siemens DP/AS-Interface Link 20E Manual

Using the Command Interface
3.1

Command Interface of the DP/AS-Interface Link 20E

Note
A special function block (FC ASI_3422) is available for the AS-i commands in a
SIMATIC S7 DP master. This FC handles the command protocol described below
independently (see Section 3.2).
You will find FC ASI_3422 in the programming example on the diskette supplied
with the printed version of this manual.
Significance and Functionality
Via the command interface, you can control the response of the AS-i master
completely from within your user program.
AS-i commands are read and written using the acyclic services of PROFIBUS-DP
V1. In the user program on the DP master, you use the services read_record and
write_record (data record 2).
DP master
Acyclic services
write_record
S
Command job
Send buffer
Status nibble
in the DP in-
put area
read_record
S
Command response
Receive buffer
for response
data or
error/status
information
Figure 3-1
66
DP/AS-i Link
Data record 2
Í Í Í Í Í Í
Status information
Í Í Í Í Í Í
PROFIBUS
ADR
BF DP-AS-Interface
Link 20
DIA
29 24 19 14 9 4 SF
28 23 18 13 8 3 APF
27 22 17 12 7 2
CER
31 26 21 16 11 6 1 AUP X 2
3 4
30 25 20 15 10 5 0 CM
Í Í Í
6GK7 1415 2AA0
Í Í Í
Í Í Í Í Î Î Î
Í Í Í Í
Í Í Í
Í Í Í Î Î Î
Î Î Î Î Î Î Î
Î Î Î Î
Î Î Î Î
Í Í Í
Î Î Î Í Í Í
Î Î Î
AS-Interface
DP/AS-Interface Link 20E
C79000-G8976-C138–04
AS-i slaves
AS-i
slave 1
AS-i
slave 2
AS-i
slave n
Release 11/2002