Illustration 4.34 Control Word and Reference
The frequency converter is to receive a start command and
the reference is to be set to -50% (-2000 Hex) of the
reference range.
The reference value is first converted to 1' complement,
and then 1 is added binarily to obtain 2' complement:
2000 Hex 0010 0000 0000 0000 0000
1' complement 1101 1111 1111 1111 1111
+ 1
2' complement 1110 0000 0000 0000 0000
Table 4.17 Reference Value
Control word = 047F Hex ⇒ Start command.
Reference = E000 Hex ⇒ -50% reference.
Illustration 4.35 Resulting Control Word and Reference
4.7.11 Present Output Frequency
Illustration 4.36 Present Output Frequency
The value of the frequency converter's present output
frequency is transferred as a 16-bit word. The value is
transferred as whole numbers 0 to±32767 (±200%).
16384 (4000 Hex) corresponds to 100%.
Output frequency has the following format:
0-16384 (4000 Hex) ≅ 0-100% (Parameter 201 Output
frequency low limit-Parameter 202 Output frequency high
limit).
Example - Status word and current output frequency:
The master receives a status message from the frequency
converter that the current output frequency is 50% of the
output frequency range.
Parameter 201 Output frequency low limit = 0 Hz
Parameter 202 Output frequency high limit = 50 Hz
Status word = 0F03 Hex.
Output frequency = 2000 Hex ⇒ 50% of the frequency
range, corresponding to 25 Hz.
Illustration 4.37 Status Word and Output Frequency
Programming Design Guide
MG27E402 Danfoss A/S © Rev. May/2014 All rights reserved. 115
4 4
To Next Page
Loading...
Need help?
General