Product Overview; Control Structures; Control Structure Open Loop; Local (Hand On) And Remote (Auto On) Control - Danfoss VLT FC51 Design Manual

Product Overview

3 Product Overview

3.1 Control Structures

3 3
Select open loop or closed loop in 1-00 Configuration Mode.

3.1.1 Control Structure Open Loop

Reference
handling
Remote
reference
Auto mode
Hand mode
Local
reference
scaled to
Hz
LCP Hand on,
off and auto
on keys
Illustration 3.1 Open Loop Structure
In the configuration shown in Illustration 3.1, 1-00 Configu-
ration Mode is set to [0] Open loop. The resulting reference
from the reference handling system or the local reference
is received and fed through the ramp limitation and speed
limitation before being sent to the motor control. The
output from the motor control is then limited by the
maximum frequency limit.
3.1.2 Local (Hand On) and Remote (Auto
On) Control
The frequency converter can be operated manually via the
local control panel (LCP) or remotely via analog/digital
inputs or serial bus. If allowed in 0-40 [Hand on] Key on
LCP, 0-44 [Off/Reset] Key on LCP, and 0-42 [Auto on] Key on
LCP, it is possible to start and stop the frequency converter
by LCP pressing the [Hand On] and [Off/Reset] keys. Alarms
can be reset via the [Off/Reset] key. After pressing the
[Hand On] key, the frequency converter goes into hand
mode and follows (as default) the local reference set by
using the LCP potentiometer (LCP 12) or [
The potentiometer can be disabled by parameter 6-80 LCP
Potmeter Enable. If the potentiometer is disabled, use the
navigation keys for adjusting reference.
18
®
VLT Micro Drive FC 51 Design Guide
P 4-14
Motor speed
high limit [Hz]
Remote
Reference
Local
P 4-12
Motor speed
low limit [Hz]
▲ ▼
]/[ ] (LCP 11).
MG02K302 - Rev. 2013-12-03
100%
P 3-4* Ramp 1
P 3-5* Ramp 2
0%
Ramp
100%
-100%
After pressing the [Auto On] key, the frequency converter
goes into auto mode and follows (as default) the remote
reference. In this mode, it is possible to control the
frequency converter via the digital inputs and RS-485. See
more about starting, stopping, changing ramps and
parameter set-ups etc. in parameter group 5-1* Digital
Inputs or parameter group 8-5* Serial Communication.
Hand Off
On Reset
Illustration 3.2 LCP Control Keys
Local reference forces the configuration mode to open
loop, independent on the setting of 1-00 Configuration
Mode.
Local reference is restored at power-down.
To motor
control
P 4-10
Motor speed
direction
Auto
On