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
Terminal 42 Output
(setting [113]...[115] or [149]...[151], Ext. Closed Loop 1/2/3
• General Purpose I/O card MCB 101, terminal X30/8: Par. 6-60
Terminal X30/8 Output
, (setting [113]...[115] or [149]...[151], Ext. Closed Loop
1/2/3
• Analog I/O card MCB 109, terminal X42/7...11: Par. 26-40
Terminal X42/7 Output
, par. 26-50
Terminal X42/9 Output
, par. 26-60
Terminal X42/11
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 (
parameter group 21-**, Ext. Closed Loop
) can each be auto-tuned, simplifying and saving time during
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.
Enabling autotuning par. 21-09
PID Autotuning
puts the relevant PID controller into PID autotuning mode. The LCP then directs the user with on-screen
instructions.
PID autotuning functions by introducing step changes and then monitoring the feedback. From the feedback response, the required values for PID
Proportional Gain, par. 21-21
Ext. 1 Proportional Gain
for EXT CL 1, par. 21-41
Ext. 2 Proportional Gain
for EXT CL 2 and par. 21-61
Ext. 3 Proportional
Gain
for EXT CL 3 and Integral Time, par. 21-22
Ext. 1 Integral Time
for EXT CL 1, par. 21-42
Ext. 2 Integral Time
for EXT CL 2 and par. 21-62
Ext. 3
Integral Time
for EXT CL 3 are calculated. PID Differentiation Time, par. 21-23
Ext. 1 Differentation Time
for EXT CL 1, par. 21-43
Ext. 2 Differentation
Time
for EXT CL 2 and par. 21-63
Ext. 3 Differentation Time
for EXT CL 3 are set to value 0 (zero). Normal / Inverse, par. 21-20
Ext. 1 Normal/Inverse
Control
for EXT CL 1, par. 21-40
Ext. 2 Normal/Inverse Control
for EXT CL 2 and par. 21-60
Ext. 3 Normal/Inverse Control
for EXT CL 3 are determined
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
PID Autotuning
. Depending on the system being controlled the time required
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.
VLT
®
HVAC Drive Programming Guide 3 Parameter Description
MG.11.C9.02 - VLT
®
is a registered Danfoss trademark
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