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Secondary Control Units
VAV-Series Controllers
Date Last Saved: 7/7/2011 4:34:08 PM

Product Name(s): VAV-SD; VAV-SD-S; VAV-SD2A; VAViH-SD; VAV-DD; VAV-DD7
Product Description: The VAV-Series SCUs are programmable variable air volume (VAV) terminal equipment controllers that reside on the secondary polling network. Each model can be custom programmed, but is not expandable and has a variety of I/O options for common applications. They perform stand-alone operation and come with libraries of application logic for common VAV terminal equipment.
Product Application(s): The individual VAV-Series controllers are designed for the following VAV air terminal unit configurations: VAV-SD: Used for VAV terminal units requiring floating point control of external damper and valve. Includes triac outputs for control of terminal fan and stages of electric heat or floating point control of reheat valve. VAV-SD-S: Same as VAV-SD above, but approved for use in smoke control systems and inputs support only thermistor or dry contact (no support for Microset wall unit). VAV-SD2A: Same as VAV-SD above, but suited for controlling VAV series fan boxes with a variable speed fan. Also supports Alerton Microtouch, Microset and Microset II wall units. VAViH-SD: Same as VAV-SD above, but with integrated actuator. VAV-DD: Used for VAV and dual duct air terminal units requiring floating point control of external dampers. Two integral airflow sensors to provide pressure independent operation of the VAV box. Supports Alerton Microset wall unit. Control algorithms are factory-loaded into flash memory; calibration, programming, etc. stored in nonvolatile flash memory. VAV-DD7: Same as VAV-DD above, but with three additional switched outputs for control of terminal fan and stages of electric heat or floating point control of reheat valve. Supports Alerton Microtouch, Microset and Microset II wall units.
Point Quantity Characteristics
Analog Input (AI): See below Airflow (differential pressure; 0 - 1.2" w.c.)
*VAV-DD and VAV-DD7 have two airflow sensors (hot deck and cold deck).
Digital Input (DI): N.A.
Universal Input (AI or DI): See below Thermistor (3K or 10K)

Dry Contact (sourced on-board)

Single input (optional) from Microset zone thermostat (Exception: VAV-DD).
Analog Output (AO): See below Selectable 0-20mA or 0-10vDC (VAV-SD2A only)
Digital Output (DO): See below Triac switch (24vAC/0.5a). Some Triacs are ground-switched for floating damper control (requires 2 Triac pair). Remainder of Triacs are hot-switched for auxiliary equipment (fan, heat, etc.) control.
Universal Output (UO):
Control Unit Model #:AIDIUIDOAOUOOther
VAV-SD 4 5
VAV-SD-S 4 5
VAV-SD2A 4 5 2
VAViH-SD 5 6
VAV-DD 4 4
VAV-DD7 4 7
A/D Converter Resolution
8 bit
10 bit
12 bit
16 bit
D/A Converter Resolution
6 bit
8 bit
10 bit VAV-SD2A only
No Analog Output
HOA switches provided on each output?
Note: These are also available as an add-on from 3rd party vendors.
Both AO and DO
DO Only
Indicating status LED on each output?
AO and DO
AO Only
DO Only
Integral Flow Sensor? VAV-DD and VAV-DD7 have two.
Integral Damper Actuator? Model VAViH-SD only. Actuator capacity is 44 lb-in, stroke over 80 - 110 seconds.
Can controller accept occupant override from thermostat? Yes
Can controller accept occupancy sensor input? Yes
Expander Boards
Network Ports, Protocol(s), and Speed(s) Supported
(Note: See 'Architecture' for network details)
(1) - BACnet-MS/TP @ 9.6 to 76.8 kbps (polling)
External Communication Ports, Speeds and Access Devices None
Additional Information (Optional)
Network Accessing Capabilities via Controller
Access controller only via MFST
Access controller plus additional controllers on network segment / LAN
Access all controllers on system via FST-100
No access available on this controller
Controller Access Devices
Local Display Panel (controller-mounted)
Local Display Panel (zone-mounted)
Handheld Interface Device (proprietary device)
PDA (3rd-Party HID)
Zone-Based port (details below)
Zone-Based Interface Access Microset, Microset II and Microtouch zone sensors have displays and pushbuttons for accessing controller parameters. Wall sensor with interface jack allows Handheld Interface Device access to controller parameters. Not all controllers are compatible with all wall units. Refer to specific models for compatibility.
Zone Interface Hardware
Zone-Mounted touchpad (thermostat or stand-alone display)
HID (proprietary device)
PDA (3rd party HID, with software)
*Note: This section covers the capabilities for accessing the controller or other parts of the network from the controller (i.e. 'bottom-up').
Standard access functionality is covered in the Architecture and Software sections.
**Does NOT include front-end OI functions. See vendor for specific functions available.
Functions Available Through Field Interface**:View ParamsChange ParamsChange
O&M SupportTAB/Cx Support
Local Display Panel (controller-mounted)
Local Display Panel (zone-mounted)
Handheld Interface Device (proprietary device)
PDA (3rd-Party HID)
Zone-Based port (details below)
Microprocessor(s) Motorola AZ-60 with on-board flash memeory

VAV-SD-S: Motorola HCMOS processor w/ integral ROM and RAM for processor functions.
Clock Type
Powered, battery-backed
Battery powered
Powered, no battery backing
Clock Synchronization Clock synchronization is via standard BACnet Time_Synchronization message by OWS, or by any device which can transmit standard BACnet Time_Synch.
Volatile Memory (RAM) Capacity 1.0 kB
Volatile Memory (RAM) Uses
RAM use unrestricted
RAM use restricted as shown below
Information Not Provided
Program Execution / Calculation storage
Data / Trends / Alarms storage
Configuration / Parameter storage
Control Programming storage
Is Volatile Memory Supported By Battery? No
Battery Type(s) N.A.
Battery Life N.A.
Backup Battery Operating Time N.A.
Non-Volatile Memory Capacity (EEPROM/Flash)* Information not provided
Non-Volatile Memory Uses
Data / Trends / Alarms / Calculation Storage
Configuration / Parameter Storage
Control Programming Storage
Controller Operating System
Additional Information
* Items in NV memory are not lost upon power or battery failure. Other types of NV memory such as EPROM, NOVROM, etc. do not directly impact system performance.
Can trend data be stored in this controller? No
How many total trend values can be stored? N.A.
What is the controllers role in trending? Points attached to this controller can be trended, although controller takes no active role in trending.
Can controller be programmed to 'push' data to archive or are trends 'pulled' from controller?
When full, does controller automatically send up trend data, overwrite data, or stop logging data? N.A.
Programming Method(s) Alerton VisualLogic graphical programming. Optional menu-based set-up/configuration can be performed.
Resident vs Non-Resident Program Execution Local control logic is resident and executed at the control unit. The BCM (SI) controls scheduling and global (system-wide) BAS control strategies.
Resident/Supervisory. This controller supervises the scheduling of other controllers.
Resident/Stand Alone. This controller contains its own schedule.
Non-Resident. This controller is dependent upon another controller for its schedule.
None. This controller has no scheduling features.
Resident Energy Management
Energy management algorithms for this controller can be custom programmed
Pre-programmed/built-in algorithms available, and are fully editable using custom programming
Pre-Programmed/built-in with limited editing via template-based programming
Controller is not typically used for energy management functions
Specific Pre-Programmed Algorithms Available
None (custom programming only)
None (not applicable)
Optimal Start/Optimal Stop
Peak Demand Limiting/Load Shedding
Economizer (enthalpy, dry-bulb, CO2, modulating/2-position, etc.)
Additional Energy Management functions are resident at SI
Additional Programming Functions
DDC Loops (P, PI, PID) P, PI, and PID
Automatic PID Tuning Feature No
Automatical-Dial Alarm Support No
Does controller perform multiple retries and buffer/store alarm until connection is made? No
Are multiple destinations possible? No
Upon controller power loss or hardware failure:
Are network communications affected? No
Is loss recognized on/by the network and alarm reported? Yes
DO and AO response?
Outputs fail to a user pre-specified position
Outputs fail to a normal (unpowered) position
Outputs fail to last position
Volatile memory functions?
Retained for life of backup battery
Other All volatile memory functions written to EEPROM upon loss of power
Upon restoration of power does the controller:
Auto-reboot without operator intervention? Yes
Automatically reset/synchronize the clock? No
Update all monitored functions? Yes
Generate an alarm if backup battery is dead? N.A.
Upon network or communications failure does controller:
Continue to operate standalone? Yes
Operate with last global settings or user-specified value? N.A.
Do broken network segments continue to communicate within the remaining segment?
(Note: May depend on proper termination of segments for higher speed networks.)
Does network automatically reconfigure upon restoration? Yes
Does network store 'loss of communications' alarm with time of event? No
Additional Information (optional)
Self Test Diagnostics
Does controller have internal self-test diagnostics to check:
Processor failure? Yes
Internal hardware failure? Yes
Open/shortened sensor? Yes
Control Enclosure Provided as standard feature of product, UL Listed for Plenum Mounting
Power Supply Required
Voltage 24 VAC
VA 5VA Minimum (VAViH-SD, VAV-DD7: 10VA Minimum) with no Binary outputs used. 65VA Maximum (VAV-DD7: 100VA Maximum) with all Binary Outputs used.
Surge Protection Provided - Surge and lightning protection provided as standard feature.
Underwriters Laboratories UL 916 PAZX (Energy Management)

UL864 / UUKL Smoke Control System Equipment in U.S. only (VAV-SD-S)
FCC Part 15, Subpart J, Class A
CE EMC Directive 89/336/EEC (European CE Mark) (Exception: VAViH-SD)
LonMark Certified
No - but LonWorks compatible
Information not provided
BACnet (BTL) Certified
Not submitted for testing
Information not provided