Introduction; Features And Benefits - Contemporary Controls BAST-221C User Manual

1 Introduction

The BAST-221C is a member of the BASstat BACnet Communicating Thermostat series. It
provides multi-stage heating and cooling control in an attractive wall-mounted enclosure with a
large LCD display. Intended for use with rooftop units (RTUs), the thermostat can control one or
two stages of heating and one or two stages of Direct Expansion (DX) cooling. The BASstat is
BACnet compliant and BTL listed to ensure seamless integration into BACnet networks. There
are two models with the only difference being the way the thermostat communicates to a
BACnet client. One model (B2) is BACnet MS/TP connected and can be routed to BACnet/IP
clients using a BASrouter
be integrated into any 802.11 b/g/n Wi-Fi network. User-side comfort control is accomplished
with six buttons – Mode (Heat, Cool, or Ventilation), Fan, Raise (Up Arrow), Lower (Down
Arrow), Set, and Power. There also are options to lock select buttons or all buttons on the
thermostat. A large and easy to read LCD display indicates setpoint, space temperature and
current mode of operation using graphical icons.
The BASstat has a built-in space temperature sensor with provision for remote wired 3kΩ NTC
thermistor sensor or temperature value can be sent by another communicating device over the
BACnet network. Both models have five relays – two for stage heating, two for stage cooling
and one for fan. The BASstat is configurable using its buttons and entering the Engineering
Menu or via a network connection to a BACnet client. Contemporary Controls' free
Discovery Tool can be used for initial discovery and configuration of the thermostat over
BACnet. Control algorithm parameters such as deadband, proportional gain, integral rate, stage
trip points and stage widths are all configurable. The BASstat also features configurable short-
cycle protection, maximum cycles per hour, fan control and occupancy selection. All states and
pending delays are indicated by graphical icons on the thermostat display.
The numerous features available in the BASstat can be configured by the systems integrator to
meet user requirements in two different ways. One way is using a button sequence on the
thermostat in order to enter the Engineering Menu - which requires physical access to the
thermostat. Optionally, the buttons could be locked to limit user access to Engineering Menu
after installation is complete. The second method is configuring the thermostat over the BACnet
network using a BACnet client device or software such as Contemporary Controls' free
Discovery Tool (BDT). All features available are configurable using both methods.
1.1

Features and Benefits

Fully stand-alone thermostat algorithm or fully BACnet network-controllable
•
BTL listed with B-ASC device profile for seamless integration into BACnet networks
•
24VAC (+/-10%) power input
•
Manual-changeover or Auto-changeover control types
•
• Two models of thermostats for BACnet communication options:
-B2 model - BACnet MS/TP with baud rate selections up to 76.8kbps
-BW2 model -BACnet/IP over Wi-Fi model can be integrated into any 802.11 b/g/n Wi-Fi
network
Suitable for single to multi-stage heat/cool control applications with manual or automatic
•
changeover between heating and cooling modes
UM-15090000-AA4
(BASRT-B). The other model, (BW2) is BACnet/IP over Wi-Fi and can
BACnet
BACnet
Page 4