Q4C Series 4 Sensor Digital Controllers

Jamie Jolliffe 2025-11-07 9:03 AM • QEL’s Four Channel Gas monitoring and Control System is a set of remote digital sensors, such

as M-Series sensor/transmitter and Q-Series smart sensor, working with onboard relays and

optional BACnet BAC-Box together, they are monitored and controlled by the Q4 Controller.

QEL sensor/transmitters comprise a group of remote mountable sensors complete with electronics,

most of which have both analog and digital communications, and most of which have display and

onboard relay options.

The Q4 Four Channel Controller is a microprocessor based and a flexible programmable

controller with capability to work with up to four QEL digital sensor/transmitters through its RS485 smart/digital sensor port. With 4 onboard relays, the controller can assign any one (or up to

four) of the four digital sensor/transmitters to each relay. The Controller also equips a USB port to

allow traditional Windows PC software, M-View, to access the Controller config database.

Additional RS-485 port can be programmed through Menu to either work as a Modbus RTU port

for BAS or SCADA (as default) or work as a BACnet port to connect QEL BAC-Box, which

supports BACnet/IP protocol.

Additional features include 24 VDC transistor outputs for strobe light and horn as well as an onboard buzzer.

The enclosure for the Q4 Controller is rated IP66 & NEMA 4, 4X, 12 & 13 and is UL listed.

Relay status indicator and RS-485 communication indicator are visible at the front of the

enclosure.

Power supply is designed for 24VDC/AC for all devices in the system. QEL can supply a

transformer for external mounting sized to the application if requested.