5.2.3 Reference Handling
The reference handling in FC Series is an advanced
mechanism that sums up references from different sources.
For more information on reference handling, refer to the
FC Series Design Guide
.
Illustration 5.2 Reference Handling
The reference, or speed set point (MRV, sent via
POWERLINK), is always transmitted to the frequency
converter in percentage format as integers represented in
hexadecimal (0-4000 hex).
Depending on the setting of
3-00 Reference Range
the
reference and MAV are scaled accordingly:
Illustration 5.3 Scaling of MAV and Reference
NOTE
If
3-00 Reference Range
is set to
[0] Min - Max
, a negative
reference is handled as 0%.
The speed limit settings are depending on
0-02 Motor
Speed Unit
and can be set to RPM or Hz. If
0-02 Motor
Speed Unit
is set to RPM: The speed limit parameters
4-11 Motor Speed Low Limit [RPM]
and
4-13 Motor Speed
High Limit [RPM]
limit the actual frequency converter
output. If
0-02 Motor Speed Unit
set to Hz: The speed limit
parameters
4-12 Motor Speed Low Limit [Hz]
and
4-14 Motor
Speed High Limit [Hz]
limit the actual frequency converter
output.
4-19 Max Output Frequency
limits the maximum output and
can also influence the maximum speed of the motor.
For reference and MAV formats, see
Table 5.3
.
MRV/MAV
Integer in hex
Integer in decimal
100%
4000
16.384
75%
3000
12.288
50%
2000
8.192
25%
1000
4.096
0%
0
0
-25%
F000
-4.096
-50%
E000
-8.192
-75%
D000
-12.288
-100%
C000
-16.384
Table 5.3 Reference and MAV Formats
NOTE
Negative numbers are formed as a complement of two.
NOTE
The data type for MRV and MAV is 16-bit standardised
value, which can express a range from -200% to +200%
(8001 to 7FFF).
1-00 Configuration Mode
set to
[0] Speed open loop
.
3-00 Reference Range
set to
[0] Min - Max
.
3-02 Minimum Reference
set to 100 RPM.
3-03 Maximum Reference
set to 3000 RPM.
MRV/MAV
Actual speed
0%
0 hex
100 RPM
25%
1000 hex
825 RPM
50%
2000 hex
1550 RPM
75%
3000 hex
2275 RPM
100%
4000 hex
3000 RPM
Table 5.4
5.2.4 Process Control Operation
In process control operation
1-00 Configuration Mode
is set
to
[3] Process
.
The reference range in
3-00 Reference Range
is always
[0]
Min-Max.
- MRV represents the process setpoint.
- MAV expresses the actual process feedback (range
±
200%).
How to Control the Frequenc...
MCA 123 POWERLINK Operating Instructions
MG92C102 - VLT
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