15-8 Control Communication - Field Busses and Protocols Rexroth IndraDrive FCS01.1
DOK-INDRV*--FCS01*****-IB01_EN-P
Profibus Telegram Structure
PCD Useful Data Section (PCD)
In process data section PCD, control words and command values are
transmitted from the master to the converter, and status words and actual
values are sent from the converter to the master. The structure of the
PCD section is always identical in the sequence of its elements (words),
but is designated in different ways depending on the direction of data flow
master ⇒ converter / converter ⇒ master.
The structure of the process data section of the useful data is as follows:
Payload Abbr. Length
[bit]
Significance Contents
Control
word
CTW 16 Job
telegram
contains control bits (e.g.
release, quick-stop, error
confirmation)
Status
word
STW 16 Response
telegram
contains status bits (e.g. FC
is running, error)
Command
values
(max. 3
available)
CV1..3 16 or 32 Job
telegram
e.g. frequence setpoint,
position setpoint, torque
setpoint
Actual
values
(max. 3
available)
AV1..3 16 or 32 Response
telegram
e.g. actual frequency value,
actual position value, actual
torque value
Fig. 15-10: Process data section of the useful data
1. word 2. word 3. word 4. word
PCD section with
1x16 bit setpoint
CTW
STW
SP1
AV1
PPO type
1,3
PCD section with
up to 3
16 bit setpoints
CTW
STW
SP1
AV1
SP3
AV3
SP2
AV2
PPO type
2.4
PCD section with
1x32 bit setpoint
value and 1x16 bit
CTW
STW
SP1
AV1
SP2
AV2
PPO type
2.4
Fig. 15-11: Structure and sequence of the process data section