Informacione tehnologije IT'15 SISTEM ZA KONTROLU AMBIJENTA U STAKLENIKU AMBIENT CONTROL SYSTEM IN GREENHOUSE Tomče Velkov, Ace Panev, Roman Golubovski, Sašo Gelev, Vlatko Čingoski, Goce Stefanov and Maja Kukuseva Paneva Faculty of Electrical Engineering, UGD - Stip, R.Macedonia Sadržaj: Za postizanje dobrog rasta useva zasađenih u staklenik, neophodno je iskoristiti sva znanja o tome koje uslove moramo zadovoljiti da bi dobili očekuvanu žetvu. Nekoloko klimatskih faktora su važni da bi se razvio održlivi ambijenat unutar staklenika, a to su temperatura, vlažnost vazduha, vlažnost zemljišta, cirkulacija vazduha kao i njihov međusobni odnos. Ovaj rad objašnjava kako se savremena tehnologija može iskoristiti u jednom automatizovanom računarskom sistemu za kontrolu stanja u unutrašnjosti staklenika, upotrebljavajući određeni hardver (senzore, aktuatore, embeded upravljač i personalni računar za SCADA interfejs). Prikazano rešenje upravlja klimatskim faktorima na efikasan način, koristeći asinhroni komunikaciski protocol između LabVIEW bazirane SCADA na host straini i C bazirane akvizicije podataka i pokrenuti sistem na embedded PIC platformi. Abstract: In order to achieve a good growth of crops planted in a greenhouse, it is essential to implement the knowledge concerning specific conditions that need to be fulfilled to support expected harvest. In general several climate factors are important to be developed for sustainable ambient inside a greenhouse - temperature, air humidity, soil moisture, air circulation and also the relations between these factors. This paper depicts how contemporary technologies can be employed in an application of an automatic computerized system for controlling a stable environment inside a greenhouse, using affordable hardware (sensors, actuators, embedded controller and personal computer for SCADA interface). The presented solution controls the climate factors in an efficient way using an asynchronous communication protocol between a LabVIEW based SCADA on the host side, and a C based data acquisition and actuation system running on an embedded PIC platform. 1. INTRODUCTION Greenhouses Environment Control Systems form an important part of the agriculture and horticulture sectors in our country as they can be used to grow plants under controlled climatic conditions for optimal harvest (production). Appropriate environmental conditions are necessary to support plant growth, improved crop yields, and efficient use of water and other resources. The soil moisture, the air temperature and humidity govern the plant growth [1], [2]. Automating the control of the named three parameters ensures a reliable environment avoiding constant presence of human factor. The automation of the process variables relies on data acquisition for constant monitoring of all three with sufficient frequency compatible to the real dynamics of their fluctuations over time or in cases of abrupt disturbances, as well as on the proper actuation of the control variables having impact on the environment. The technical focus of this article is a simple, yet powerful solution for achieving the goal using an affordable PIC based process controller, equipped with cheap sensors for monitoring temperature and humidity, as well as affordable laptop/desktop host PC running a "homemade" LabVIEW based user interface in a form of SCADA, that is used to set the control variables and perform all necessary processing, calculations and logging of important data. 2. THE CONCEPT The concept of the working solution is given in figure 1. The process controller is a PIC, equipped with analog and digital I/O. Through its multiplexed A/D converter it acquires three sensors for monitoring the corresponding process variables (PVs) - the air temperature and humidity, and the soil moisture. The PIC packs and transmits the acquired data for asynchronous serial communication with the SCADA host. It also listens for commands from the host for actuation of the control variables (CVs). Through the D/A converters the PIC controls a pump for water irrigation; a motor for opening/closing a window for air conditioning against the outside temperature and humidity; a heater for increasing the inside temperature; and a ventilator for air circulation when humidity regulation (in combination with the window) is needed. The SCADA host receives the acquired PVs via RS232 serial link, presents them in their user interface (UI) gages and indicators, calculates commands for the actuators to modify/sustain appropriate values of the corresponding CVs, and transmits them via the serial link to the embedded PIC.