Parameters and properties
42
SIPROTEC PROFIBUS-DP - Communication profile
C53000-L1840-B001-03
2.5.2.2 Telegram in output direction
Figure 2-4 Event list: Output telegram with handshake byte
The individual bits of the handshake bytes “Control_O” have the meaning indicated in
Figure 2-5.
Handshake mechanisms are referred to in chapter 2.5.3.
Figure 2-5 Handshake byte “Control_O” (output direction)
Message block
number
Acknowledgement of receipt and evaluation of the message blocks in the telegram.
The PROFIBUS-DP master copies the message block number from the handshake
byte "Control_I" of the input telegram to the handshake byte "Control_O" of the output
telegram, following evaluation of the message blocks.
The PROFIBUS-DP slave repeats an message block until the message block number
of the "Control_I" byte is mirrored back correctly by the master in the "Control_O" byte.
Control_O
SPARE (reserved = 0)
Commands, Measured values
Byte offset = 0
Byte offset = 1
from: byte offset = 2
up to max.: byte offset = 99
...
etc.
Control_O
reserved = 0Message block no.
01234567
Bit position
Meaning