Siemens SIMATIC NET CP 5613 Manual page 214

Description of the DP Functions, Data, and Error Codes
Length Bytes
Each bit in the length bytes has a special meaning.
Bit
0 to 5
6
7
Example of a Special ID Format
The following table shows an example of a special ID format.
Octet
1
2
3
4 to 6
214
Number of data units
0 (decimal) means:
63 (decimal) means:
(for the length of the data units see bit 6)
Length
0 means: a data unit is one byte long
1 means: a data unit is two bytes long
Consistency
0 means: consistency over byte or word
1 means: consistency over the entire length
Bits in the byte
1 1 0 0 0 0 1
1 1 0 0 1 1 1
1 1 0 0 0 1 1
Meaning
1 data unit
64 data units
Meaning
Input/output,
1
3 bytes of vendor-specific data
1 Consistency, output, 16 words
1 Consistency, input, 8 words
Vendor-specific data
DP Base Programming Interface for CP 5613/CP 5614
C79000-G8976-C108-02