Physical Read" Commands - Siemens SIMATIC MV500 Operating Instructions Manual

9.3.2.4

"PHYSICAL READ" commands

Supported MV commands
Using the "PHYSICAL READ" command, you can read out various MV commands (Machine
Vision commands).
The following commands are supported:
Table 9- 24 PHYSICAL-READ
CMD OFFSET ADDR_
BUFFER TAG
0x70 Offset in 0x0000
the
"TXREF"
send buff-
er
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
SIMATIC MV500
Operating Instructions, 03/2021, C79000-G8976-C494-05
LEN_DATA
Length of the data to be fetched from
the reader:
• ≥ code length +2
• = 01
• ≥ match string length +2
CMD_STRUCT
Value
0x70
0x00
0x00
≥ length of the result string
0x00
Process interfacing via an automation system (PLC, PC)
RXREF
Data fetched from the reader:
• Trigger and result string
• Program number
• Match string
9.3 Control with Ident profile
165