Siemens SIMATIC ET 200pro - Figure D-2: Byte Arrangements in the Format Big Endian

Data formats and data records
SIMATIC – ET 200pro motor starter
GWA 4NEB 950 5661-02 DS 04
D-5
D.3 Data records
Writing / reading data records with STEP7
You can access the data records of the motor starter from the user program.
• Writing data records:
S7-DPV1 master: By starting SFB 53 ’WR_REC’ or SFC 58
S7-Master: By starting SFC 58
• Reading data records:
S7-DPV1 master: By starting SFB 52 ’RD_REC’ or SFC 59
S7-Master: By starting SFC 59
Note
SFC 58 and 59 cannot be used for PROFINET. These components only
work
with PROFIBUS.
For PROFINET, use the components SFB 52 or 53. These also work with PROFI-
BUS.
Other information
You will find additional information on the SFBs
• in the reference manual
'System software for S7-300 / 400, system and standard functions'
• In the STEP7 online help
Byte arrangements
When data is stored that is longer than one byte, the bytes are arranged as fol-
lows ("big endian"):
Figure D-2: Byte arrangements in the format 'big endian'
Byte 0
Byte 1
High byte
Low byte
High byte
Low byte
High byte
Low byte
High word
Low word
Data type
Byte 0
Byte 1
Byte 0
Byte 1
Byte 2
Byte 3
Byte 0
Byte 1
Byte arrangement
Byte
Word
Double word