Hardware test code is now included in this program
An externally bound version is available for use in Open Systems
File naming conventions have changed slightly
additional network variables provided to allow setting of setpoint deadbands
7R fan coils now support optional Sontay speed selector and setpoint trim (4b2)
support of configuration parameter changes, from a zone controller when open bound has been provided for the 'eXternally bound' version, this did not work correctly on earlier versions.
This is the first of an evolving range of Fan Coil
Controllers, the eventual aim is to have one set of generic Fan Coil code which will run
on any of the hardware platforms. This issue uses four separate files. The driver
configuration options allow a wide range of output possibilities. Automatic Fan Speed
control is provided for multi speed fan applications.
The configuration variable structures have been upgraded to also store the units of the
parameters. This now means that temperature parameters can be displayed in C or F on Zone
Controllers ZON3c1 onwards. These changes are required for the USA market.
The FCU controllers are registered to a Boiler Controller, this must be at least BLRxx3a7
(latest issue hardware 'C') or Floor Controller FLR3a1. In most respects the FCU
controller behaves in a similar manner to a Slave Zone Controller, it is registered as a
Zone. One major difference is that it does not have it's own Occupation times and so does
not do it's own Optimum Start. A Zone Controller is required to provide these facilities
for any number of FCUs.
In order to talk to FCU controllers with Doorway the SLT needs to be upgraded to issue 3a5
or later. It is possible to use the [#] addressing method (last service pin pressed) if
the SLT available is not 3a.
Zone controllers used with FCU's must be ZON3b1 or later running on latest large memory
hardware, earlier versions will not recognise FCU controllers for registration.
The registration procedure for all modes is the same as for
registering Slave Zones to a Master Zone. Put the Master Zone Controller into config then
register each FCU in turn. The zone will report SLVE 2 (for FCU 2, 3 for FCU 3 etc.) The
Master Zone will be set automatically to SPMD 3 when a Fan Coil is slaved to it, to allow
the Fan Coils to receive the Setpoint and Occupation information.
The FCUs are put into the same group as the Master Zone, any number of FCUs can be linked
to a single Master.
The Return air sensor must be fitted and the SPTY must be
set to 0 or 1.
Note the Occupation and Setpoint data is only updated every minute so be patient when
commissioning, operationally this is OK because the change will normally come from the
Optimum start routines which are checked every minute. If the setpoint is changed on the
Master Zone (with the knob) the new setpoint is sent straightaway.
Occupancy control SPTY 0
The AHU can be left to control from it's own setpoint but Occupancy is controlled from
a single Zone controller by registering the FCU to the Zone. The FCU will control to a
constant Return air setpoint regardless of the heating or cooling demands from the Zone.
If a supply air sensor is fitted then the off-coil temperature will be controlled within
the limits defined by MAXH, MINH, MAXC, MINC.
Setpoint supervision SPTY 1
This is the default mode of operation. The FCU(s) will control the return air (during
optimum start and occupation) to the setpoint defined by the Zone Controller.
The FCU Return Air setpoints can be individually adjusted using the SPTR setpoint trim
config variable to adjust for local conditions.
If a supply air sensor is fitted then the off-coil temperature will be controlled within
the limits defined by MAXH, MINH, MAXC, MINC.
The Return air sensor is not fitted. The mode must be set
to (SPTY) 2.
Supply Temperature scheduled to Heat and Cool demands from Zone SPTY 2
If a Supply Air sensor is fitted the Fan Coil will schedule the temperature of the supply
air (off coil) according to the Heat and Cool demands from the Zone Controller. Remember
that the Zone Controller will only provide cooling demands if it's setpoint deadband SPDB
is not set to zero.
The setpoint for the Supply Air control is calculated from the MAXH, MINH config limits
for heating demands and from the MAXC, MINC limits for cooling demands.
If there is no sensor fitted the Heat or Cool demand from the Zone will be used to
directly control the output stages, this mode is also used to 'slave a FCU' to another
FCU.
The supply sensor can be replaced by a switch which when
made will force the FCU to Occupied. On FCF or BLR boards the external connection is made
to 'input a', thus retaining the use of the supply sensor.
This is achieved by adding an extra config variable input mode INMD. The following values
are supported.
0 normal operation input measures Off Coil temperature
1 Occupied is External AND normal occupation (window contact)
2 Occupied is External OR normal occupation (outside normal hours)
3 Occupation controlled by external signal only
4 Input used as an external alarm, alarm state defined by ALST
If the switch is wired in series with a 10K resistor and a 10K potentiometer Occupied/ Non
occupied plus a 5 degree trim (operational only whilst occupied) is possible. The trim is
slightly non linear (the applied resistance is affected by the parallel resistance on the
board which helps linearise the thermistor when fitted, mechanical centre position of the
pot gives -0.7C) The zero point can be adjusted to give the correct (0 trim) by backing
off any error using the software trim SPTR. Suggest pot is marked Hotter/Colder or +/- !
A resistance between 0 and 20K ohm will be considered to be Occupied, non Occupied is
guaranteed for resistance values above 100K. The voltage generated by the pot will be
converted to a setpoint Trim only for control modes SPTY 0 or 1
The controller will automatically control fan speed, if the
multi-speed fan driver is used. If either the heating or cooling demand is greater than
90% for a period longer than FPRD (seconds/10 to match other periods) then the fan speed
will be incremented up to the next speed. If both the heating and cooling demand is less
than 10% then the Fan Speed is reduced after the same delay time. While occupied the
controller will maintain a minimum of Fan Speed 1.
Provision is made for the fan speed to be controlled from a network variable
(nviFanSpeed), from a (hotel style) zone controller for example, if this network variable
is non zero then this will override the automatic fan speed control.
This allows one 'master FCU' to provide the Return Air
control for a large space and to send its HeatOp and CoolOp outputs to one or more 'Slave
FCU's'
The Master must be operating in mode SPTY 0 or 1, i.e. must be measuring and controlling
Return temperature.
The 'Slave' must be operating in mode SPTY 2. The registration process involves putting
the master into config mode and then pressing the registration button on all the 'Slave
FCU's'.
The Slaves are put into the same group as the Master FCU, any number of Slaves can be
linked to a single Master.
If a Slave FCU is subsequently linked to a Zone Controller the link to the Master AHU will
automatically be broken.
Any FCU can act as a source of setpoint (and
occupancy) information for a group of FCUs which are all controlling to their local Return
Air sensor.
This would be useful when one FCU has a local Trim Pot (or Occupancy
switch) and the same setpoint is required on other FCUs feeding the same area of the
building.
Put the 'master' into config and 'slave' the other FCUs. The Slave FCUs will receive the
mid point setpoint (C1 SPFC plus any external Trim) of the Master, local additional trim
can be applied to each FCU using SPTR. To maintain balance amongst the FCUs the setpoint
deadband SPDB should be the same in all units within the group.
In this way a Zone Controller can provide Setpoint and/or Occupancy information to a
'master FCU' within each separate space, these FCUs can have local User Adjustments (for
the cheapskates who won't buy Zone Controllers) or Occupancy overrides, these modified
conditions are then sent to all FCUs within the area.
There are no limits on the number of FCUs which can be slaved to a 'master FCU'. A Slave
FCU can also be a 'master' to a further group of FCUs, although this only makes sense if
these FCUs are operating in mode SPTY 2;either Off Coil only control or in Driver only
mode (no sensors fitted).
Two override options are now available from Doorway
This functions exactly the same as for a Zone Controller, Switch 1 set to zero selects Override mode and the state of switch 2 determines occupancy state.
The syntax
[Zn]W1(S)/Auto/Override/10/12/W2(S)
provides a single click to a dialog box which sets the correct state for both switches. The text can be changed to suit the application and the numbers determine the colours which are used to display the text.
This option allows the Fan Coil outputs to be manually set for balancing or general testing. This uses switch 5 to select manual or hand mode and the value of MANL to set the output levels.
The syntax
[Zn]W5(S)/Hand/Auto/12/10/C18(V)
brings up a dialog box which allows Hand or Auto to be selected and also the value of the output to be entered in a text box or changed with a slider bar. The output can be set anywhere in the range 100 (full heat) to (-100) full cool. Note C18 is the configuration variable MANL this needs to match the index in the config tables for the version of code being used.
| code | Hardware | Part Number | |
| FCUD4b1 | ACT-DIN-3R | 0006/0001 issue J12 | 512 prom |
| ACT-DIN-3T | 0018/0001 issue E5 | 512 prom | |
| FCUR4b1 | FCT-DIN-4R | 0020/0001 issue E4 | 512 prom |
| FCUF4b1 | FCU-DIN-7R | 0023/0001 issue A | 512 prom address swapped |
| FCUA4b1 | ACT-DIN-AOP | 0016/0001 issue E7 | 512 prom |
Secondary Supported Hardware (special order) |
|||
| code | Hardware | Part Number | |
| FCUB4b1 | BLR-DIN-RLY | 0004/0002 issue C5 | 512 prom address swapped |
Controllers which are intended to be used with third party binding tools can be specified to have the Software switch set to enable external binding, this is indicated by an X in the file name ahead of the issue number e.g. FCURX4b1. Fan Coil Controllers Controllers so specified also support PIR detectors to change between Standby and full Occupancy. These controllers have additional functionality as defined by this specification.
This has been included to allow hardware to be re-tested at the final booking out station and also to be easily checked at any time in the field.
The controller is put into test mode by setting config 120 to 1 or by holding the service pin down as the unit is powered up. If the later method is used then the unit will need to be re-registered after the test since this action also clears any slaving which might have been setup. The first time the controller is powered after changing the prom also initiates Test mode.
Test mode is cleared by power cycling or by setting C120 back to 0.
Test mode cycles the outputs, and flashes the leds see full test specification. The values for the analogue inputs and the potentiometer can be monitored on configs 170 onwards.
Improvements have been made to the information provided to the user by the LEDs on the Controller.
This version of the Fan Coil controller uses the extended universal driver which includes a special driver type for Heat Pumps. This allows one relay to select heating or cooling and a single bank of relays to bring on the heat pump stages.
An additional configuration variable has been included to allow for Airside Damper control. This parameter sets the nominal mid point of the damper travel, the position where no heating or cooling is provided. If this mid point value is set (not zero) then the driver parameters should be set as in the following table.
| HTYP | HSTG | CTYP | CSTG | FTYP | FSTG |
| 1 | 2 | 1 | 0 | 6 | 1 |
This will cause the cooling demands to be redirected to the same relays as the heating driver (redirected output). The Fan parameters should of course be set to the required Fan type.
These have been changed to a new more flexible approach. A
single parameter for each driver type is provided which sets up the on delay or run on
time for the fan or pump.
HDLY
if negative sets the on delay in minutes for the fan or pump
if positive sets run on time in minutes for fan or pump to run after heating shut down
Typically negative values will be used for wet batteries to
provide start up protection against frost and positive (run on-) values would be used with
electric heating batteries.
The same features are available for cooling using CDLY.
The selection of OCC or OSS is now made by setting OCCO to
1 on controllers where the control is only required when the building is in occupation.
The default is for control during OSS and OCC.
This is defined with a config parameter FRPT and it defines the
controllers action when it receives a 'frost alarm' from the boiler controller.
| FRPT | action |
| 0 | no action (default) |
| 1 | heating output to 50% |
| 2 | heating output to 50% and pump/fan enabled |
The FCU controller supports sensor fail SENF alarm, this is
raised if the Return Air sensor fails and the FCU is in a mode which requires the Return
Air temperature. The Input Mode can also be set up to generate an alarm for either a short
or open circuit on terminals 'temp a', see later.
Alarm mode and Alarm State config variables have been added to the config variable list.
| ALMD | action |
| 0 | alarms ignored |
| 1 | alarms reported no other action |
| 2 | control output set to zero on alarm |
| 3 | STOP alarm recognised, control set to zero |
Alarm State determines which input state 0 or 1 is considered to be the alarm condition
when using external input for the alarm as set by INMD.
There are three plots setup as normal on the first three
'sensors'.
Plot 1 Supply air temperature
Plot 2 Return Air temperature
Plot 3 Heat/cool output -100 to +100 (negative for cooling)
The plot routine use configurable
plots.
The plots are now automatically re-scaled within the
controller to achieve the best resolution for the data recorded. This happens at the end
of every 96 readings when new maximum and minimum settings are calculated and also if a
new value is outside the current range settings.
Will support registration of up to 8 Acuators, Acuator
Drivers, Pump ChangeOvers just like a regular Zone.
Fan Coil Controllers are addressed with [Zn] where n is the
Fan Coil Zone number 1-200. [Fn] is also supported.
Sub modules are addressed as follows
Actuators [Z1Am] m=1 to 8
Item codes follow the normal conventions