QCS-21146E System Controller

COSYS Building Controls



Our COSYS Application and System Controls work along with our enterprise software platform OspreyFMS to provide a meaningful context.

The QCS-21146E is a fully programmable, Native BACnet® Building Controller that communicates on Twisted-Pair Ethernet 10-BaseT using BACnet IP and BACnet over Ethernet, or on an RS-485 LAN using the BACnet MS/TP protocol. The QCS-21146E is designed for a wide-range of applications that have medium local I/O requirements.


  • Super capacitor for real-time clock and SRAM backup which requires no maintenance
  • Supports 12 BACstat network sensors for room sensing and control or 2 Field Modules for I/O expansion
  • Fully programmable in GCL+
  • Actuator power terminal (24 VAC) for each analog output (can be powered internally or from an auxiliary transformer)
  • Firmware upgrade and database load/save over the network
  • Optional field upgrade to Modbus® RTU with hardware key
  • Service port
  • Screw or DIN rail mountable
  • LED indicator for output, power, CPU and SCAN status


The QCS-21146E is suitable for controlling various packaged units and equipment with medium I/O requirements such as small air handling units, boilers
and chillers.

The fully programmable QCS-21146E can be tailored to specific applications by creating and modifying BACnet objects and GCL+ programs.


BACnet Device Profile
BACnet Building Controller (B-BC)

11 Universal Inputs (10-bit) supporting:
0-5 VDC
0-10 VDC
10 kΩ Thermistor
Dry Contact (using 10 kΩ Thermistor jumper setting)
4-20 mA

6 Binary TRIAC Outputs (jumper configured for internal or external power)
4 Analog Outputs (0-10 VDC)

Device Addressing
Set via DIP switches and jumpers, or software setup

Removable screw-type terminal connectors

Wiring Class
Class 2 / SELV

24 VAC 50/60 Hz @ 14 VA, 86 VA with fully-loaded Binary Outputs

16-bit processor
2 MB (16-megabit) flash memory
319 KB SRAM memory for database Real-time clock
Super capacitor for 72-hr backup of real-time clock and SRAM

Communications Ports
Ethernet (10-BaseT)
BACnet IP, BACnet over Ethernet

2 RS-485 NET1, NET2 supporting:
BACnet MS/TP up to 76800 bps, max 99  devices per port
Up to 76800 bps, max 12 devices owith no more than 2  DFM devices (1 port only)

Optional Modbus up to 68400 bps, max 5 devices (1 port only)

Serial RS-232
BACnet PTP, up to 38400 bps

0° to 55°C (32° to 131°F)
10 to 90% RH (non-condensing)

26.2 x 10.7 x 4.9 cm
(105/16 x 4¼ x 115/16 in.) with housing

435 g (0.959 lbs) with housing


C-UL Listed
UL 916 Listed
BTL Listed


Order the QCS-21146 with the desired options according to the following product numbers:

QCS-21146   System Controller 11 inputs, 4 analog outputs, 6 binary outputs