Siemens CP 243-2 installation instructions ReadAS-iSlaveParameterString, Byte Meaning

Command Interface

5.2.29Read_AS-i_Slave_Parameter_String

Purpose

With this call, a parameter string complying with AS-i slave profile 7.4 can be read from the AS-i slave with the AS-i slave address specified in the send buffer.

The AS-i master supplies up to 223 bytes of reply data. The actual number of parameter bytes sent by the AS-i slave is signaled by the AS-i master in byte 2 of the receive buffer (number of parameter bytes).

If the AS-i slave sends a string longer than 220 bytes, the AS-i master aborts the string transfer and terminates the job with an error. The received data are then not made available to the user program.

As long as the string transfer is active, there is no user/analog data exchange with the addressed AS-i slave.

Structure of the Job Data in the Send Buffer

Bank

2

2

Byte

0

1

Meaning

Command number 41 H

Slave address

Structure of the Job Data in the Receive Buffer

Bank

2

2

2

2

2

...

...

...

Byte

0

1

2

3

4

...

...

...

Meaning

Echo of the command number 41 H

Command status

Number of parameter bytes

String byte (1)

String byte (2)

.....

String byte (n±1)

String byte (n)

Maximum value for n=220

SIMATIC NET CP 243-2 AS-i Master	5-55
C79000-G8976-C142/02