Siemens SIMATIC MV500, Operating Instructions Manual, Page: 199 / 294

Process interfacing via an automation system (PLC, PC)
9.6 Control via TCP/IP and RS232
SIMATIC MV500
Operating Instructions, 03/2021, C79000-G8976-C494-05
199
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.
It is only possible to overwrite a match string if the optical reader is in processing mode and
matching was activated during program saving for the current program. If the match string
cannot be overwritten, an entry is made in the diagnostic data.
The following command must be sent to overwrite the match string:
Table 9- 54 Command for overwriting the match string
Structure / description
Character no.
0 1 2 3 4 5 6 7 … n-1 n
Meaning Command identifier More significant byte
of the length "m" of
the following match
string
Less significant byte
of the length "m" of
the following match
string
New match string with a
length "m"
Val-
ue/character
M A T C H 0x00 ... 0xFF 0x00 ... 0xFF All printable characters
Note that saving the new match string is not persistent. 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 characters of the command must be sent as a contiguous command. If the spacing
between the individual characters is too large, receipt of the new match string is aborted.
The characters 5 and 6 are interpreted as an unsigned 16-bit word and form the overall
length of the new match string starting at character 7.
9.6.3 Setting/resetting DISA bit
Set DISA bit
Use this command to set the DISA bit.
String: "MDIH" (Machine command set DIsable signal High)
Reset DISA bit
Use this command to reset the DISA bit.
String: "MDIL" (Machine command set DIsable signal Low)