D-1
Communications Processor CP 541
EWA 4NEB 812 6188-02
DP Parameter Assignment Message
The CP 541 needs the parameter assignment message in the DP start; it is
explained here. The DP master sends the DP parameter assignment message
to the DP slave (CP 541).
The parameter assignment message contains 7 bytes of data, byte 0 to byte 6.
It is structured according to DP Standard DIN E 19254, Part 3.
The structure of the 7 bytes according to the DP standard can be found in
Table D-1.
Table D-1
Structure of the DP Standard Section of the Parameter Assignment
Message
Byte
Value
Meaning
0
Station status
1
1
0 ... FF
H
Watchdog factor
These two bytes represent two factors for the response
monitoring time
2
0 ... FF
H
monitoring time.
The response time is calculated with the following for-
mula: T
WD
10 ms
factor 1
(byte 1)
factor 2
(byte 2)
3
0 ... FF
H
Response delay (min. T
SDR
)
This entry is not significant with the CP 541 because
parameter min. TSDR must be permanently entered via
DB1 as parameter SDT 1.
4, 5
001F
H
Manufacturer identifier
The manufacturer identifier is a product-specific ID. The
CP 541 only accepts in the parameter assignment mes-
sage the manufacturer ID corresponding to the own ID.
If the ID in the parameter assignment message does not
agree with the own ID, an error message is issued.
6
Group identifier
Two or more DP slaves can be grouped with group iden-
tifier.
1
Meanings of the individual bits of the station status are given in Table D-2.
Introduction
Structure
DP Standard
Section
D
