Section 1
ZGARD CX II Controller
General Information and Specifications
The ZGARD CX II Controller is an advanced microprocessor-based monitoring system designed to interface
with remote gas sensors and perform user configured control functions for surveillance, activate ventilation
equipment, personnel alert or alarm indication. The controllers feature audible and visual status indicators with
relay outputs. The controller will automatically detect the total number and type of the remote sensors, actively
residing on the RS485 network. Additional remote relay modules can also be tagged on the communication
bus, creating a control and surveillance gas alarm monitoring system.
The ZGARD CX II Controller provides programmable operating parameters, which are organized by a menu
interface with keypad and LCD screen. Standard features include a large LCD Screen, audible-visual indication
and relay contact outputs. The remote gas sensors are connected via RS485 serial communication ports
managed by the ZGARD CX II Controller; up to 99 sensors can be employed. The ZGARD CX II Controller
acting as the host governs the digital RS485 serial communication and automatically coordinates the remote
devices. MSA ZGARD S or GS sensor-transmitters are available to detect a wide variety of gases including
Carbon Monoxide, Carbon Dioxide, Nitrogen Dioxide, Refrigerants and Ammonia.
OPERATING SPECIFICATIONS
Remote Sensor Input
RS485 digital data bus, 2-wire connection plus shield
Network Capacity
99 Remote Gas Sensors
Power Requirements
19-27 VAC, 50/60 Hz or 24-38 VDC, at 0.3 Amps
19-27 VAC, 50/60 Hz at 0.7 Amps (with STROBE OPTION)
To be powered by a class 2 source
Operating Temperature
Storage Temperature
-20° to 50°C (-4° to 122°F)
-30° to 60°C (-22° to 140°F)
User Interface
Keypad on the front panel of the controller with menu driven operating parameters
Digital Display Screen
4 Line x 40 Character backlit LCD Screen displays the operating, alarm and fault diagnostic
status of the system. The display is split in two display mode sections
Status Display
Common LED’s for System OK-Green, Caution- Amber, Warning-Amber and Alarm-Red
Power-Green, Fault-Red, Communication-Red & Green
Network Communication
RS485, 2-wire serial communication for remote gas sensors and auxiliary modules
Auto-Configuration Feature
Digitally recognized remote devices (Sensors and Auxiliary Modules). Each device residing
on the RS485 serial data bus shall be automatically assigned as a Node on the network
Caution/Warning/Alarm
Setpoints
Adjustable from 1 to 99% of operating range for each system sensor type
Number of Relays
4 assignable DPDT Relays: Relay1, Relay2, Relay3 & Relay4
Remote Relay Modules (RRM)
Up to 8 OPTIONAL RRM’S can be connected to the controller. Each relay module adds 4
assignable DPDT relay outputs. These relays are freely assignable from within the CX II
configuration menu
Relay Contacts Rating
5 Amps , 250Vac.
5 Amps, 30Vdc.
Relay Action
A Caution, Warning & Alarm relay can be defined as Normally Energized or De-Energized
and Latching or Non-Latching. A Fault relay is always normally-energized and non-
latching.
Relay Time Delays
Menu selected OFF delays, adjustable from 0 to 600 seconds for Caution, Warning and
Alarm, effectively common to all active channels
Event Logging
Event logging of every status change with time & date stamp. Events are stored in non-
volatile memory and can be viewed on LCD Screen or sent to printer via RS-232 port. Up
to 20,000 events can be stored. Most recent events over-write oldest events.
Serial Interface
MODBUS interface allows retrieval of system status including individual sensor data
Optional BACnet module allows for integration into BACnet systems
Set-up and Calibration
Pre-configured at factory to default settings and configurable by user
Audible Alarm
Audible Alarm Device, 93 dB @ 0.3 meters
Pushbutton
Alarm Silence feature
Enclosure
Polycarbonate, Water- and corrosion-resistant enclosure
Dimensions
7” (117 mm) H x 10” (254 mm) W x 3.75” (95 mm) D
Weight
3kg (6 lbs.)
Certification
UL / CSA 61010-1-2012 File No. 3118354
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