Siemens SIMATIC MV550 S Operating Instructions Manual page 115

Requirement for matching with 1D/2D codes
All match options ("All", "Position", "ID", "GS1") are supported for 1D/2D codes. The match
string that is sent must be formatted in such a way that the information required for the
match can be extracted.
Command: Write match string
● This MV command allows the match string of the currently loaded program (non-
persistent) to be overwritten. This command can only be executed when the optical
reader is in processing mode. If the reader exits processing mode, for example by
changing to STOP mode or to the group error status, the overwritten match string is
discarded. This also applies to a program change.
● The structure of the memory area is outlined in the table below.
● The total length of the data to be written is the overall length of the match string + 3 bytes
for the length and the command identifier ("CMD_STRUCT.LEN_DATA = n + 3").
● If the new match string is applied to the current program, the command receives positive
acknowledgment.
If the match string cannot be overwritten, an extra entry is made in the diagnostic data.
Table 9- 14
Parameter
CMD
OFFSETBUFFER
EPCID_UID
LEN_DATA
ADDR_TAG
Table 9- 15
Address
0x0000
0x0001
0x0002
0x0003
...
n + 2
n + 3
SIMATIC MV500
Operating Instructions, 05/2019, C79000-G8976-C494-02
CMD_STRUCT
Value
0x71
0x00
0x00
Match string length + 3
0x00
Memory area of the receive data (TXREF or RXREF)
Value
0x03
0x00 ... 0xFF
0x00 ... 0xFF
--
--
--
--
Process interfacing via an automation system (PLC, PC)
Meaning
Command identifier
"Write match string"
Length of match string high byte
Length of match string low byte
1st character of the match string
...
(n-1)th Characters of the match string
nth Characters of the match string
9.3 Control with Ident profile
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