AS-Interface
Profibus-DP
Subject to reasonable modifications due to technical advances.
Copyright Fuchs, Printed in Germany
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is
s
u
e
d
a
te
1
2
.1
0
.1
9
9
9
40
Byte 2: Start address of the user memory window in the output data telegram
(write user memory)
Byte 3: Length of the user memory window in the output data telegram
If user memory bytes shall only to be read or written, the appurtenant length
byte has to be set to 0.
If no user memory bytes shall be transmitted it is recommended to set the user
memory statement to FF
hex
FF
hex
FF
hex
FF
hex
.
The maximum length of the user memory window is 128 bytes.
• AS-i configuration data and AS-i (startup) parameters (62 bytes)
For each AS-i slave 2 bytes are used. AS-i slave 0 is disregarded.
In the first byte, the AS-i configuration data is specified. The AS-i ID-code is
coded in the byte's high nibble and the I/O-configuration in its low nibble.
In the second byte's low nibble, the AS-i (startup) parameters are transmitted.
The upper half of this byte is unused.
Furthermore during the operation of the system AS-i parameters can be trans-
mitted via Profibus in the management channel as described above (command
write parameter).
The default parameter for an AS-i slave is F
hex
, so that normally as second byte
0Fhex is stated.
If a slave address is to remain unused, either FF
hex
, FF
hex
or 256
hex
, 256
hex
has to be entered.
The configuration of the DP-slave (I/O data fields) has to be adjusted according
to the highest AS-i slave address.
Example: Parameter telegram for the professional mode:
3 AS-i slaves and transmission of user memory, all slaves AS-i ID 0
Slave 1: 4 inputs
Slave 2: 4 outputs
Slave 3: 2 inputs, 2 outputs
from user memory byte 0 read 4 bytes of user memory
no writing of user memory
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
ID-code
IO-configuration
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
0
0
0
0
P3
P2
P1
P0
unused (=0)
AS-i parameter
user mem. st.
slave 1
slave 2
slave 3
slave 4
slave 31
conf
ID,IO
par
conf
ID,IO
par
conf
ID,IO
par
conf
ID,IO
par
conf
ID,IO
par
20
00
04
00
00
00
0F
08
0F
03
0F
FF
FF
...
FF
FF
