How to Control the Frequenc...
A negative response may look like this:
PCA
PCA
IND
IND
PCV
PVA
PVA
PVA
PVA
STW
STW
PCD
MAV
MAR
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
CTW
MRV
PCD
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.
MG90U302
Operating Instructions
Byte
Value
1
70
2
00
3
00
4
00
5
00
6
00
7
00
8
02
9
0F
10
07
11
20
12
00
......
9
......
PCD
PCD write
Danfoss A/S © Rev. 2014-02-27 All rights reserved.
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
STW
MAV
PCD
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).
......
9
......
PCD
PCD read
6
29
6
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