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7.2.3.8
Read AS-i slave parameter string (Read_Parameter_String)
Meaning
For AS-i slaves with the profile 7.4, this call can be used to read a parameter string from the
AS-i slave with the specified AS–i slave address.
The AS-i master supplies up to 220 bytes of reply data. The AS-i master signals the actual
number of parameter bytes sent by the AS-i slave in Byte 2. The maximum number of
parameter bytes is 220.
If the AS-i slave sends a string longer than 220 bytes, the AS-i master aborts string transfer
and terminates the job with an error. The received data is not made available to the user
program.
While transmission of the string is running, there is no transfer of user data / analog data with
the addressed AS-i slave.
Structure of the utility RDREC − Index 27
Byte
Bit 7
0
1
2
3
4
...
221
222
AS-i master CM 1243-2 and AS-i data decoupling unit DCM 1271 for SIMATIC S7-1200
Manual, 04/2013, A5E02655230010A/RS-AA/003
Bit 6
Bit 5
String byte 219 (possibly irrelevant)
String byte 220 (possibly irrelevant)
7.2 Description of the AS-i line calls and AS-i slave calls
Meaning
Bit 4
Bit 3
Version_hi = 0x00
Version_lo = 0x00
Number of string bytes
String byte 1
String byte 2
...
Using the data record interface
Bit 2
Bit 1
Bit 0
87
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