Siemens SIMATIC MV550 S Operating Instructions Manual page 120

Process interfacing via an automation system (PLC, PC)
9.3 Control with Ident profile
Command: Trigger and read result string
To activate a trigger and read the result string, you will need to send a "READ" command
with address "0x0000". The table below shows the content of the memory area of the receive
data specified in the command ("CMD-STRUCT").
The total length of the result string is stored at the (virtual) addresses "0x0000" and
"0x0001".
Note that if the result string is longer than the number of characters to be read
("CMD_STRUCT.LEN_DATA"), the end of the string is truncated. If the result string is shorter
than the number of characters to be read, the string is padded with the value "0x00".
You can also configure the format text so that the result bits "READ", "MATCH", "N_OK" are
inserted in the string.
If you do not want to know the total length of the result text, send a "PHYSICAL READ"
command starting at the address "0x0002" ("CMD_STRUCT.ADDR_TAG = 2").
You can also start to read from any start address, for example, when the result string is only
relevant starting at the 10th character in the code.
Table 9- 25
Parameter
CMD
OFFSETBUFFER
EPCID_UID
LEN_DATA
ADDR_TAG
Table 9- 26
Address
0x0000
0x0001
0x0002
0x0003
...
(n + 1)
(n + 2)
120
CMD_STRUCT
Value
0x70
0x00
0x00
≥ length of the result string
0x00
Memory area of the receive data (TXREF or RXREF)
Value
0x00 ... 0xFF
0x00 ... 0xFF
--
--
--
--
--
Meaning
Length of the entire result string (more significant
byte)
Length of the result string (less significant byte)
1st character of the result string
2nd character of the result string
...
(n–1)th character of the result string
nth character of the result string
Operating Instructions, 05/2019, C79000-G8976-C494-02
SIMATIC MV500