Reference Handling - Danfoss VLT AQUA Drive FC 202 Design Manual

Product Overview
Figure 2.13 Active Reference
Local
reference
Figure 2.14 Configuration Mode
Application control principle
Either the remote reference or the local reference is active
at any time. Both cannot be active simultaneously. Set the
application control principle (that is, open-loop or closed-
loop) in 1-00 Configuration Mode, as shown in Table 2.4.
When the local reference is active, set the application
control principle in 1-05 Local Mode Configuration.
Set the reference site in 3-13 Reference Site, as shown in
Table 2.4.
For more information, refer to the Programming Guide.
MG20N622
Design Guide
P 1-00
Con guration
mode
open loop
Scale to
RPM or
Hz
Local
ref.
Scale to
closed loop
unit
closed loop
Danfoss A/S © 09/2014 All rights reserved.
[Hand On] Reference Site
[Auto On] 3-13 Reference Site
LCP Keys
Hand Linked to Hand/Auto
Hand⇒Off Linked to Hand/Auto
Auto Linked to Hand/Auto
Auto ⇒Off
Linked to Hand/Auto
All keys Local
All keys Remote
Table 2.4 Local and Remote Reference Configurations

2.4.4 Reference Handling

Reference handling is applicable in both open-loop and
closed-loop operation.
Internal and external references
Up to eight internal preset references can be programmed
into the adjustable frequency drive. The active internal
preset reference can be selected externally through digital
control inputs or the serial communications bus.
External references can also be supplied to the drive, most
commonly through an analog control input. All reference
sources and the bus reference are added to produce the
total external reference. The external reference, the preset
reference, the setpoint, or the sum of all three can be
selected as the active reference. This reference can be
scaled.
The scaled reference is calculated as follows:
Y
Reference = X + X ×
100
Where X is the external reference, the preset reference, or
the sum of these references and Y is 3-14 Preset Relative
Reference in [%].
If Y, 3-14 Preset Relative Reference, is set to 0%, the scaling
does not affect the reference.
Remote reference
A remote reference is comprised of the following (see
Figure 2.15).
•
Preset references
•
External references:
- Analog inputs
- Pulse frequency inputs
-
Digital potentiometer inputs
- Serial communication bus references
•
A preset relative reference
•
A feedback controlled setpoint
Active Reference
2
Local
Local
Remote
Remote
Local
Remote
23
2