Advertisement
DP communication relations
Communication according to PROFIBUS DP, i.e. DIN
19245 part 1 & 3, is supported. Consequently a
master that supports PROFIBUS DP must be used.
PPO description
A special feature of the PROFIBUS Profile for VSD's is
the communication object called a PPO, meaning
Parameter-Process Data Object.
The PPO is well suited for fast cyclical data transfer,
and may, as the name implies, carry both process
data and parameters.
The selection of PPO type is made according to the
master request.
A PPO may consist of a parameter part and process
data part. The parameter part can be used for
reading and/or updating the parameters one by one.
PPO. Parameter-Process Data Object
By DP one of the following shown PPO's must be used:
PCD: Process Data
PCV: Parameter-Characteristics-Value
PCA: Parameter-Characteristics (Bytes 1, 2)
PCA handling below
IND:
Subindex (Byte 3), (Byte 4 is not used)
PVA: Parameter value (Bytes 5 to 8)
CTW: Control word
see page 22
STW: Status word
MRV: Main reference value
MAV: Main actual value (Actual output frequency)
16
FCM 300 PROFIBUS / VLT 2800 PROFIBUS
By DP communication one of the parameter-process
data objects (PPO's) described below must be used.
The process data part consists of a fixed part (4
bytes) and a parametrable part (8 or 16 bytes). In the
fixed part control word and speed reference are
transfered to the VLT while status word and actual
output frequency feedback are transfered from the
VLT. In the parametrable part the user chooses which
parameters have to be transfered to (parameter 915)
and which from (parameter 916) the VLT.
Type 1, 2 and 5 consist of the parameter part and 4,
12 and 20 byte process data, respectively.
Type 3 and 4 consist of 4 and 12 byte process data,
respectively.
MG.90.A2.02 – VLT is a registered Danfoss trademark
Advertisement
