Siemens SIMATIC MV440 Operating Instructions Manual page 264

Process interfacing via an automation system (PLC, PC)
10.3 Control with FB 45 and Ident profile
Command: Read program number
To have the current program number returned when a READ command is received, the MV
command "Read program number" (WRITE command) must be sent immediately before,
see WRITE commands/MV command interface (Page 248).
The READ command must specify the start address 0x0000 and a length of 0x1
("MOBY_CMD".address_MDS or "PIB_COMMAND".StartAddress = 0, "MOBY_CMD".length
or "PIB_COMMAND".Length = 1).
The byte read at address 0x0000 contains the number of the program currently selected and
is stored in the command data area specified in the command
("MOBY_CMD".DAT_DB_number or "instance DB-RFID standard profile".RXREF) after the
command is processed.
Table 10- 34 Moby_CMD
Command
Table 10- 35 PIB_COMMAND
Parameter
CMD
OffsetBuffer
UID
Length
StartAddress
Table 10- 36 Command data area (FB45: Data DB, RFID standard profile: TXBUF or RXBUF)
Address
0x0000
262
Sub_
[hex] Command
[hex]
02 -
Length Address_
[dec] MDS [hex]
1 0
Value
0x70
0x00
0x00
0x01
0x00
Value
0x0 – 0xF
DAT_DB_number DAT_DB_address
[dec]
Number of the Pointer to the start
data DB (for example
48)
FB45 stores the read result data here.
Meaning
Current program number
SIMATIC MV420 / SIMATIC MV440
Operating Instructions, 04/2013, A5E02371045-06
[dec]
word
(for example 0)