A negative response may look like this:
Byte Value
PCV
PCA 1 70
PCA 2 00
IND 3 00
IND 4 00
PVA 5 00
PVA 6 00
PVA 7 00
PVA 8 02
PCD
STW 9 0F
STW 10 07
MAV 11 20
MAR 12 00
Table 6.8 Negative Response
RC is 7 Hex, which means that the request has been
rejected, and the fault number can be found in the PVA
part. In this case the fault number is 2, which means that
the upper or lower limit of the parameter is exceeded, see
Table 6.5.
6.3
Process Data
Use the process data part of the PPO for controlling and
monitoring the frequency converter via the PROFINET.
6.3.1
Process Control Data
Process data sent from the PLC to the frequency converter
are defined as Process Control Data (PCD).
0
1 2 ...... 9
CTW MRV PCD ...... PCD
PCD write
Table 6.9 Master Slave
PCD 0 contains a 16-bit control word, where each bit
controls a specific function of the frequency converter, see
chapter 6.4 Control Profile. PCD 1 contains a 16-bit speed
set point in percentage format. See chapter 6.3.3 Reference
Handling.
The content of PCD 2 to PCD 9 is programmed in 9-15 PCD
Write Configuration and 9-16 PCD Read Configuration.
6.3.2
Process Status Data
Process data sent from the frequency converter contain
information about the current state of the frequency
converter.
0 1 2 ...... 9
STW MAV PCD ...... PCD
PCD read
Table 6.10 Slave Master
PCD 0 contains a 16-bit status word, where each bit
contains information regarding a possible state of the
frequency converter.
PCD 1 contains per default the value of the current speed
of the frequency converter in percentage format (see
chapter 6.3.3 Reference Handling).
The content of PCD 2 to PCD 9 is programmed in 9-16 PCD
Read Configuration.
6.3.3
Reference Handling
The reference handling in FC 102/FC 202/FC 301/FC
302/FCD 302 is an advanced mechanism that sums up
references from different sources.
For more information on reference handling, refer to the
FC 102/FC 202/FC 301/FC 302/FCD 302 Design Guides.
Illustration 6.1 Reference Handling
The reference, or speed set point (MRV, send via PROFINET
is always transmitted to the frequency converter in
percentage format as integers represented in hexadecimal
(0-4000 hex).
How to Control the Frequenc...
Operating Instructions
MG90U302 Danfoss A/S © Rev. 2014-02-27 All rights reserved. 29
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