No. 02: Write_Parameter - Siemens SIMATIC ET 200SP Manual

9.4.3

No. 02: Write_Parameter

Meaning of the command
The command transfers an AS-i slave parameter value. The AS-i master subsequently
makes a parameter call to the addressed AS-i slave and passes the parameter value to the
AS-i slave in this call. The slave sends the parameter echo as receipt acknowledgment to
the master. The value of the parameter echo is sent in the reply data of the command.
The parameter value is only stored in the volatile memory of the AS-i master and is not
transferred to the EEPROM as a configured parameter!
The AS-i slave can provide any parameter echo value. As a general rule, the returned
parameter echo value is not a "mirror image" of the parameter value that is sent by the
master to the slave. If necessary, refer to the documentation of the AS-i slave to ascertain
whether the echo value has a special meaning.
This command is not permissible for AS-i slaves that meet AS-i slave standard profile 7.4.
For these slaves, the AS-i master itself administers the AS-i slave parameter assignment.
Structure of the job data in the send buffer
Table 9- 10 Structure of the job data in the send buffer
Byte
Bit 7
0
1
2
Structure of the response data in the receive buffer
Table 9- 11 Structure of the response data in the receive buffer
Byte
Bit 7
0
AS-Interface master CM AS-i Master ST (3RK7137-6SA00-0BC1)
Manual, 07/2017, A5E02655262020A/RS-AD/004
Meaning
Bit 4 Bit 3
Command number: 02
Slave address
0
Meaning
Bit 4 Bit 3
0
Using the command interface
9.4 Description of the AS-i commands
H
Parameter value
Parameter echo
Bit 0
Bit 0
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