Control Structure Open Loop; Local (Hand On) And Remote (Auto On) Control - Danfoss VLT AQUA Drive FC 202 Design Manual

Introduction

2.9.2 Control Structure Open Loop

2 2
Reference
handling
Remote
reference
Auto mode
Hand mode
Local
reference
scaled to
RPM or Hz
LCP Hand on,
o and auto
on keys
Illustration 2.10 Open Loop Structure
In the configuration shown in Illustration 2.10, 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 maximum frequency allowed limits the output from
the motor control.
2.9.3 Local (Hand On) and Remote (Auto
On) Control
The frequency converter can be operated manually via the
LCP or remotely via analog/digital inputs or serial bus.
If allowed in 0-40 [Hand on] Key on LCP, 0-41 [Off] Key on
LCP, 0-42 [Auto on] Key on LCP, and 0-43 [Reset] Key on LCP,
it is possible to start and stop the frequency converter by
LCP using the [HandOn] and [Off] keys. Alarms can be
reset via the [Reset] key. After pressing the [Hand On] key,
the frequency converter goes into Hand Mode and follows
(as default) the local reference set by pressing the
navigation keys [
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 various serial
interfaces (RS-485, USB, or an optional fieldbus). See more
about starting, stopping, changing ramps and parameter
set-ups in parameter group 5–1* Digital Inputs or
parameter group 8–5* Serial Communication.
22
Design Guide
Remote
Reference
Linked to hand/auto
Local
P 3-13
Reference
site
▲ ▼
] and [ ].
Danfoss A/S © Rev. 06/2014 All rights reserved.
P 4-13
Motor speed
high limit [RPM]
P 4-14
Motor speed
P 3-4* Ramp 1
high limit [Hz]
P 3-5* Ramp 2
Ramp
P 4-11
Motor speed
low limit [RPM]
P 4-12
Motor speed
low limit [Hz]
Hand
on
Illustration 2.11 LCP Control Keys
Hand Off
Auto
LCP Keys
Hand
Hand ⇒ Off
Auto
Auto ⇒ Off
All keys
All keys
Table 2.8 Conditions for either Local or Remote Reference
Table 2.8 shows under which conditions either the local
reference or the remote reference is active. One of them is
always active, but both cannot be active at the same time.
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.
100%
0%
100%
-100%
P 4-10
Motor speed
direction
Auto
O Reset
on
Reference Site Active Reference
3-13 Reference Site
Linked to Hand/ Local
Auto
Linked to Hand/ Local
Auto
Linked to Hand/ Remote
Auto
Linked to Hand/ Remote
Auto
Local Local
Remote Remote
To motor
control
MG20Z202