Siemens SIMATIC NET CP 142-2 Manual page 46

B8976111/02
4.2.1.3 Write_Parameter
Meaning
With this call, a parameter value is transferred and sent directly via the AS-i bus to the addressed AS-
1 slave. The parameter is saved only temporarily on the CP 142-2.
The AS-i slave transfers the current parameter value in the response. This can deviate from the
values that have just been written according to the AS-i master specification (/2/). The slave response
is entered in the parameter echo field.
The RECEIVE job to "fetch" the parameter echo is optional. Normally, the parameter echo is not
evaluated in the S7 program.
Structure of the job data in the send buffer
Bit 7
Byte 0 0 H
Byte 1
Byte 2 0
Structure of the job data in the receive buffer
Bit 7
Byte 0 0
4.2.1.4 Read_Parameter
Meaning
This call returns the current parameter value (actual parameter) of a slave.
Structure of the job data in the send buffer
Bit 7
Byte 0 0 H
Byte 1
Structure of the job data in the receive buffer
Bit 7
Byte 0 0
Bit 0
2 H
Slave address
Parameter
Bit 0
Parameter echo
Bit 0
3 H
Slave address
Bit 0
Parameter echo
4-9
AS-i Master Module CP 142-2