Danfoss FC 300 Design Manual page 27

FC 300 Design Guide
Reference Handling
Local Reference
Remote Reference
The reference handling system for calculating the remote reference is shown in the illustration
below.
The remote reference is calculated once every scan interval and initially consists of
two parts:
1.
2.
The two parts are combined in the following calculation: Remote reference = X + X * Y / 100%.
The catch up / slow down
digital inputs on the adjustable frequency drive. They are described in par. group 5-1*.
The scaling of analog references is described in par. groups 6-1* and 6-2*, and the scaling of
digital pulse references is described in par. group 5-5*.
Reference limits and ranges are set in par. group 3-0*.
X (the external reference): A sum (see par. 3-04) of up to four externally selected ref-
erences, comprising any combination (determined by the setting of par. 3-15, 3-16 and
3-17) of a fixed preset reference (par. 3-10), variable analog references, variable digital
pulse references, and various serial bus references in whatever unit the adjustable fre-
quency drive is controlled ([Hz], [RPM], [Nm], etc.).
Y- (the relative reference): A sum of one fixed preset reference (par. 3-14) and one
variable analog reference (par. 3-18) in [%].
function and the
MG.33.B9.22 - VLT ® is a registered Danfoss trademark.
3. Introduction to FC 300
freeze reference function can both be activated by
3
27