Main Menu - Extended Closed Loop - Group 21; Ext. Closed Loop - Danfoss VLT Programming Manual

®
VLT HVAC Drive Programming Guide

3.19 Main Menu - Extended Closed Loop - Group 21

3.19.1 21-** Ext. Closed Loop

The FC 102 offers 3 Extended Closed Loop PID controllers in addition to the PID Controller. These can be configured independently to control either
external actuators (valves, dampers etc.) or be used together with the internal PID Controller to improve the dynamic responses to setpoint changes or
load disturbances.
The Extended Closed Loop PID controllers may be interconnected or connected to the PID Closed Loop controller to form a dual loop configuration.
In order to control a modulating device (e.g. a valve motor), this device must be a positioning servo motor with built-in electronics accepting either a
0-10V (signal from Analog I/O card MCB 109) or a 0/4-20 mA (signal from Control Card and/or General Purpose I/O card MCB 101) control signal.
The output function can be programmed in the following parameters:
• Control Card, terminal 42: Par. 6-50
• General Purpose I/O card MCB 101, terminal X30/8: Par. 6-60
1/2/3
• Analog I/O card MCB 109, terminal X42/7...11: Par. 26-40
Output
(setting [113]...[115], Ext. Closed Loop 1/2/3
General Purpose I/O card and Analog I/O card are optional cards.
3.19.2 21-0* Extended CL autotuning
The extended PID Closed Loop PID controllers (
commissioning, whilst ensuring accurate PID control adjustment.
To use PID autotuning it is necessary for the relevant Extended PID controller to have been configured for the application.
A graphical Local Control Panel (LCP) must be used in order to react on messages during the autotuning sequence.
PID Autotuning
Enabling autotuning par. 21-09
instructions.
PID autotuning functions by introducing step changes and then monitoring the feedback. From the feedback response, the required values for PID
Ext. 1 Proportional Gain
Proportional Gain, par. 21-21
Gain for EXT CL 3 and Integral Time, par. 21-22
Integral Time for EXT CL 3 are calculated. PID Differentiation Time, par. 21-23
Time for EXT CL 2 and par. 21-63 Ext. 3 Differentation Time
Control Ext. 2 Normal/Inverse Control
for EXT CL 1, par. 21-40
during the tuning process.
These calculated values are presented on the LCP and the user can decide whether to accept or reject them. Once accepted, the values are written to
the relevant parameters and PID autotuning mode is disabled in par. 21-09
to carry out PID autotuning could be several minutes.
Excessive feedback sensor noise should be removed using the input filter (parameter groups 6-**,5-5* and 26-**, Terminal 53/54 Filter Time Constant/
Pulse Filter Time Constant #29/33) before activating PID autotuning.
Terminal 42 Output (setting [113]...[115] or [149]...[151], Ext. Closed Loop 1/2/3
Terminal X30/8 Output
Terminal X42/7 Output
parameter group 21-**, Ext. Closed Loop
puts the relevant PID controller into PID autotuning mode. The LCP then directs the user with on-screen
Ext. 2 Proportional Gain
for EXT CL 1, par. 21-41
Ext. 1 Integral Time for EXT CL 1, par. 21-42
Ext. 1 Differentation Time
for EXT CL 3 are set to value 0 (zero). Normal / Inverse, par. 21-20
for EXT CL 2 and par. 21-60
PID Autotuning
MG.11.C9.02 - VLT ® is a registered Danfoss trademark
3 Parameter Description
, (setting [113]...[115] or [149]...[151], Ext. Closed Loop
Terminal X42/9 Output
, par. 26-50 , par. 26-60
) can each be auto-tuned, simplifying and saving time during
for EXT CL 2 and par. 21-61
Ext. 2 Integral Time for EXT CL 2 and par. 21-62
for EXT CL 1, par. 21-43
Ext. 3 Normal/Inverse Control
for EXT CL 3 are determined
. Depending on the system being controlled the time required
3
Terminal X42/11
Ext. 3 Proportional
Ext. 3
Ext. 2 Differentation
Ext. 1 Normal/Inverse
189