Read_Mv - Siemens SIMATIC Ident Function Manual

Configuring the instructions
4.5 Programming instructions
4.5.2.3

Read_MV

The "Read_MV" instruction reads the read result of an optical reader. The "Read"
instruction must be used to read the configuration. The length of the data to be read is
calculated automatically by the instruction based on the length of the created receive
buffer. The actual length of the read result is output in the "LEN_DATA" output
parameter. The data will be saved in the "IDENT_DATA" data buffer. If the buffer is too
small, the error message "0xE7FE0400" appears and the expected length is output at
"LEN_DATA".
To achieve an optimum speed, we recommend that you adapt the length of the data type
"IDENT_DATA" so that this is as close as possible to the maximum expected length of
the read result (2 bytes code length + read code).
Figure 4-7
Table 4- 16 Explanation for the instruction "Read_MV"
Parameter
IDENT_DATA
LEN_DATA
36
Instruction "Read_MV"
Data type
SINT[10]
INT
Default values Description
0 Read result
The length of the read code is locat-
ed in bytes 0 and 1.
Note:
When necessary, an array of any size
can be transferred to this parameter.
Note that the array must be ≥ 10
Length of the read result ≙ 2 bytes
bytes long (e.g. "SINT[12400]").
0x00
code length + read code
Ident profile, Add-on instruction for Rockwell systems
Function Manual, 07/2020, C79000-G8976-C410-04