Beckhoff Building Automation 30.04.2015 1 New Automation Technology HVAC-Library Exercise Heating...

Beckhoff Building Automation 18.04.23 1

New Automation Technology

HVAC-Library Exercise Heating Circuit


In the following exercise is the programming of a heating circuit stepwise described.

Function:This installation is a static heating circuit in which the flow temperature is controlled in accordance with the outside temperature.

The actuator for the heating circuit valve is a three-point actuator.

The heating circuit can be switched into night setback mode by a switching timetable.




The programming takes place with pre defined Macros.

The macros are composed of TwinCAT Export-Files:

The HVAC-Macros are located in the folder: ….\EXP_Files\subprograms.Fore a better overview the sub programs are classified in sub folders.




For using the macros there are some adjustments in TwinCAT necessary. At [Projekt] Options you get in the menu Editor from TwinCAT. There you have to adjust the fond and tab width.






The base program must be loaded first before the macros can be used. The System programs folder is located within the base program. The programs are used to initialise global variables.

Please open the Projekt : Base_Program.pro


In the base program the following global variables are defined.

rOutside_T outdoor temperature rOutside_T_damped outdoor temperature damped bFlashFlag Blinker CtrkVoltage 230V AC, 24V DC, 24V AC bResetFault acknowledge faults

stSystemTime System time structure dtSystemTime System time date an time uiYear Year uiMonth Month uiDay Day uiDayOfWeek Day of week (0-6) uiHour Hour uiMinute Minute uiSecond Second uiMillisecond Millisecond tTaskCycleTime Cycle time Task tPLCCycleTime Cycle time PLC




1. Step. Add a folder with the name HC1 (Heating circuit one)




2. Step:

Load all the macros for the heating circuit out of the folder:EXP_Files

Heating Valve: 3Point_CtrlValve with AntiblockageE__X_3PCtrlValve_AB.EXP

PID-Controller: PID_Ctrl__X_PID.EXP

Setpoint Calculation: Setpoint_Heating_Circuit__X_SETPOINT_HC.EXP

Time Schedule: TimeScheduling_1Stage__X_TimeSchedul1St.EXP

Temperature Sensor: TemperatureSensor__X_T.EXP

Pump: Pump__X_PU.EXP




Rename all objects.

Replace the placeholder X with the plant name HC1.

Move all program blocks into the folder HC1

Result:



3. Step:


Create a main program for the heating circuit named HC1.



4. Step:


Place all subprograms from HC1 in the main program an connect them.See below!

0 -> 1 Time Scheduling transfers day or night modus

3 -> 1 Transmission freeze protection status for setpoint calculation.

1 -> 4 The heating is operating and enables the PID-Controller.

5 -> 4 The actual temperature value is transmitted to the PID.

4 -> 2 The PID is transmitting his control value to the valve.

4 -> 3 The controller is transmitting his output to request the pump depending on the valve position.



5. Step:


The heating circuit is finished now.

The call form HC1 is to add in Main.



6. Step:


Compile the program
















If another heating circuit is required, it is very efficient to proceed as follows:The name of the heating circuit is underlined in red.With the text editor we search for HC1 and replace it with HC2.This renames all the program blocks in the heating circuit macro, and all the variables that are locally declared within them. The changes are then saved in the file HeatingCircuit_3Point.exp, and the text editor is closed. After this we can import the HeatingCircuit_3Point.exp file with installation identifier HC2 .

By repeating this process, a large heat distributor with a large number of heating circuits can be programmed in a very short time.



Date post:	15-Dec-2015
Category:	Documents
Upload:	brian-hiett
View:	215 times
Download:	0 times

Beckhoff Building Automation 30.04.2015 1 New Automation Technology HVAC-Library Exercise Heating...

Documents