Process interfacing via an automation system (PLC, PC)
9.3 Control with Ident profile
SIMATIC MV500
120 Operating Instructions, 06/2018, C79000-G8976-C494-01
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 CMD_STRUCT
OFFSETBUFFER 0x00
LEN_DATA ≥ length of the result string
Table 9- 26 Memory area of the receive data (TXREF or RXREF)
0x0000 0x00 ... 0xFF Length of the entire result string (more significant
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
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