Software Features 

EZ software operates in the Microsoft Windows environment and provides a very fast, easy-to-use, menu-driven graphical user interface. In addition to a copy of Microsoft Windows, BAS also includes several useful Windows applications with the EZ System. EZ is compatible with any other Microsoft Windows-based application and can operate simultaneously with those applications in true multitasking fashion.

No previous programming experience is needed to configure or operate any aspect of the system. All system configuration is User-prompted, fill-in-the-blank. The system monitors all User input and alerts the user to any invalid entries.  

The system can toggle between any two user-selectable languages on the fly. The system is shipped in one version that includes all available language translations. All user-defined labels, such as zone descriptions or site name, can be entered and stored in both the primary and the alternate language at that site. The entire user interface, including screens, dialogs, messages, and menus, will toggle between the two selected languages.

All alarm messages and alarm, trend, security, and communication logs are stored and displayed in both selected languages. When connected remotely to a site, the remote user can be logged on to the system in a different language than a User at the local Command Center. The languages currently available on the system are Chinese and English. Other languages are being added at this time. 

The BAS VariZone® System provides tenant comfort while serving many client temperature control zones with one Server. The VariZone® Server is a single HVAC unit capable of providing both heating and cooling. The system provides the capability for both pressure-dependent and pressure-independent clients.

Client zones consist of dampers and actuators and, in some instances, fans and backup heat. The system can provide for up to 32 Servers and up to 512 Clients per Server.  

With the Graphics Builder, graphics display screens can be easily and quickly set up. Floor plans can be imported from CAD or paint programs. Dynamic graphic icons for standard HVAC components such as fans, DX coils, pumps, economizers, boilers, chillers, etc. are all menu-selectable. These icons are all dynamic and can be linked to any data in the system. 

With the graphics viewer, the user can quickly view the status of any site, building, floor, zone, or HVAC unit. All graphics viewer inputs are performed with a mouse, requiring no keyboard input.  

An identical user interface to that on the host system (the building being controlled) is available from a client site (any location remote to the Host site). Other than a communication menu for COM port settings, connect, and hang-up, the remote client interface looks and functions identical to the Host version. The software communicates over standard phone lines at 33600 baud. 

Control of all equipment is based on preprogrammed control algorithms referred to as “Equipment Schedules.” The command center contains the control algorithms for all RSCs connected to a trunk line. A separate Equipment Schedule, with the appropriate control algorithms for that equipment, is available for 64 different types of HVAC equipment.

During system configuration, an Equipment Schedule is chosen for each RSC. When an Equipment Schedule is chosen, the EZ software prompts the user to enter the parameters needed for proper unit control. The software creates a configuration file that contains all information for that RSC. The software then uses that configuration file to customize the control algorithm for that equipment. You can change the configuration files at any time.

All Equipment Schedule control algorithms are also contained in an EPROM located on the RSC. Dip switches located on the RSC are used to select which Equipment Schedule is used for RSC default control. On initial startup, or any time that communication with the Command Center is lost, the RSC takes over unit control using preprogrammed heating and cooling setpoints.  

The Equipment Schedule Editor lets you change the control algorithm for any Equipment Schedule, or create a new one. Changing the control sequence for any piece of equipment is as easy as a point-and-click with the mouse. Because this tool is so simple to use, and the results can have a major impact on equipment operation, this feature should be limited to installers only. 

The quickest building configuration can be performed by simply setting an address and equipment schedule at each RSC, connecting them to a trunk line, and energizing the system. If the Command Center finds an RSC online with no existing configuration file, a configuration file is created using system defaults.

Each Control Zone in the system can have up to 16 alarm or special control functions configured, for a total of 16,384 system alarm or control functions. These conditions are in addition to any Auxiliary Equipment or Equipment Schedule control functions.

All inputs at each RSC can be configured for any combination of alarm actions. Those alarm actions are: (1) screen display; (2) printer output; (3) log to hard disk; (4) callout to fax machine terminal; (5) callout to digital pager; and (6) take specific action. The specific action feature can turn on or off any digital output or position any analog output in the system. Master alarms can also be configured selectively throughout the system, with all regular alarm features available.  

All inputs, outputs, and most configuration data from all RSCs are available to any Windows application that conforms to the Dynamic Data Exchange specification.  

Five levels of security are available in the system. All software features and menu items are preset to a security level. A security log is maintained to keep a record of the date, time, and name of all Users logged onto the system.  

Any system alarm can be configured to be sent to a remote fax machine and/or sent to a digital pager. The fax machine will display detailed information about the alarm condition and the status of all inputs and outputs at that RSC at the time of the alarm. The pager will display a four-digit number corresponding to the Host Site Number set up during configuration.  

All RSC inputs and outputs at any zone can be stored on the hard disk for later retrieval and review. All parameters flagged in the initial system setup are logged to the hard disk once every ten minutes. A new trend log is started each month.

The Trend Log Viewer utility allows for screen display or printer hard copy of any user-selected parameters. The Trend Log also monitors and stores all setback override conditions, which can be useful in billing tenants for off-hours HVAC operation. Any alarm condition that has been configured for logging will be stored in the Alarm Log. The Alarm Log is in a text format and can be viewed or printed by any text editor.  

Up to 32 weekly schedules can be configured, each with two occupied and two unoccupied times per day. Each weekly schedule can be configured for eight days, including seven weekdays and a holiday. Any HVAC equipment or Auxiliary Equipment can use any weekly schedule.  

All 10 US federal holidays through the year 2010 are pre-configured and provided with the system. Any of these holidays may be modified, or any new holidays can be easily added.  

The standard time-of-day schedules for all HVAC equipment and Auxiliary Equipment can be overridden in one of three ways. 

The three overrides are listed in order of priority: 1) all zones in the building can be programmed for a one-time override event to either the occupied or unoccupied mode; 2) each zone or piece of Auxiliary Equipment can be individually programmed for a one-time override event to either the occupied or unoccupied mode; or 3) an input activated from the zone will override the zone to occupied for a preset amount of time.  

Override reports can be printed for any single zone or the entire building. This report will show start and stop times, length of override, and total override hours for the entire month. This report is useful for property managers to bill tenants for off-hours HVAC operation.  

All Equipment Schedules that use different setpoints for the unoccupied mode can use Smart Recovery. If the space is in unoccupied mode and below the occupied setpoint, the system will calculate a time to enter warm-up mode.

This time will be based on actual space temperature, desired occupied setpoint, outside air temperature, and recovery history for the zone. If the space is in unoccupied mode, above the occupied setpoint, and has an economizer, the system will enter cooldown mode. The software tracks actual setback recovery conditions and adjusts startup times for subsequent recoveries.  

All systems with economizers installed use dual enthalpy to determine the economizer mode. One outside air enthalpy sensor is used for all economizers in the system. Each HVAC unit with an economizer has an enthalpy sensor installed in the return air duct.  

All VAV and VariZone® Equipment Schedules can be selected to use either pressure-dependent or pressure-independent damper control. 

The latest development in VAV server control is TRAV. This concept uses input from all of the clients (zone dampers) to reset a variable frequency drive on the VAV server (rooftop air handler). The duct static pressure is allowed to vary, within preset limits, to the minimum necessary to satisfy the clients. This control strategy provides for a significant energy reduction with a corresponding increase in comfort and air quality. 

Reset of controlled temperature, based on outside air temperature, is available for several schedules. All parameters are user-defined. These include outside air shutoff temperature, maximum outside air temperature, minimum controlled temperature, maximum controlled temperature, reset ratio, and unoccupied degrees offset. 

Any piece of HVAC equipment and any piece of auxiliary equipment can be configured for kW load shedding. All equipment configured for load shedding is given a priority from 1-32. Any number of pieces of equipment can be given the same load shed priority. If building kW exceeds the preset level, the system will begin shedding equipment in priority order until kW falls below the preset demand level. 

Proportional, integral, and derivative control modes are standard. Each of these three factors may be modified by the user at each zone. 

Proportional, integral, and derivative gains can all be changed for each control zone. The user can also change the cycle rate (cycles per hour) and derivative look-back time. Default PID control parameters are provided for all Equipment Schedules and should rarely require adjustment. A zone history graph is available for all zones. The zone history will show a graph of the temperature over the most recent cycle time to aid the User in PID loop tuning. 

Both sensors can be input at any convenient RSC location. These are global values and can be used by any RSC in the system through the EnerNet communication link. 

Any digital output not used by an equipment schedule can be configured to be used for Auxiliary Equipment, such as exhaust fans, lighting control, hot water tanks, etc. Each piece of equipment can be configured for a weekly schedule, load shedding, and setback override.

The main system screen can be easily modified to change the information displayed for each zone.  

Any RSC can be placed in troubleshooting mode from the Command Center. The screen displays all RSC inputs, outputs, and communication status. Any input or output can be changed to any desired state or value. The troubleshooting screen will override all other software control functions. A custom label can be assigned to each of the inputs and outputs for clarity. 

You can select the temperature display mode from the system settings screen. All system displays, including the main system screen, troubleshooting screen, trend log, alarm log, and configuration files, will be scaled to the selected range.

An Equipment Schedule is provided to control an interior lighting system. In addition to standard time-of-day ON/OFF control, this schedule will flash the lights 5 minutes before entering the Unoccupied Mode. This will give tenants enough time to exit the building or press the setback override button before the lights turn off.