Detcon MCX-32-N4X - Manual (Page 7)

Model MCX-32
Model MCX-32 Instruction Manual Rev. 2.3 Page 1 of 49
1.0 Introduction
1.1 Description
The Detcon Model MCX-32 is a multi-channel gas detection controller designed to serve as a host monitor and
controller for a network of gas detection sensors as well as a wide range of other field devices. All MCX-32
models are configurable for up to 64 channels and can communicate with serial sensors directly via RS-485
Modbus™ and analog sensors using Detcon’s selection of I/O modules. These modules also communicate
with the controller via Modbus™ and are available in four channel sets for 4-20mA inputs, contact closure
inputs, relay outputs and 4-20mA outputs. These modules are DIN rail mounted and stackable allowing for
seamless system expansion.
Remote mounted gas detection sensors can include any analog 4-20mA or RS-485 (Modbus™) serial output
device such as toxic gas, combustible gas or oxygen deficiency sensors. Other remote field devices can
include contact closure inputs such as liquid level, temperature, pressure or smoke detection devices. The
analog sensors and field devices are interfaced to the I/O modules which communicate with the controller’s
Modbus™ port. The serial sensors interface directly with the controller’s Modbus™ port and do not require
I/O modules. Thus, the types of sensors or field devices being interfaced will dictate the I/O modules needed
for the MCX-32 controller. The controller is capable of identifying all of the attached Modbus™ sensors and
automatically setting its configuration parameters.
Also, all configuration inputs are completely field-
configurable which provides a distinctive combination of user configuration flexibility and expansion
customization.
The controller utilizes touch screen technology that displays the status of every sensor, with more detailed
information available by touching the screen. Typical sensor status includes channel number, tag name, gas
type, concentration, and alarm/fault status. Each channel provides three alarm levels (Alarm 1, Alarm 2, and
Alarm 3) and fault. Additional features include: one-touch Alarm Inhibit, Alarm Reset, and Alarm Silence
(Acknowledge) functions.
The MCX-32 controller can be powered by 110/220VAC, 20-30VDC, or both and is available in two
enclosure types. These enclosure types are NEMA 1 (N1P) and NEMA 4X (N4X). The N1P is an indoor use,
panel-mount enclosure while the N4X is an indoor/outdoor use, water/corrosion proof enclosure.
These
enclosure types are discussed in more detail in their perspective installation sections.
1.2 System Operation
The heart of the MCX-32 controller is the backlit touch screen LCD display. The controller communicates
with serial sensors and I/O modules using RS-485 Modbus™ RTU Protocol. The MCX-32 includes two
separate Modbus™ ports. These ports are used to communicate directly with Modbus™ capable sensors or
Detcon’s I/O Modules. The two ports will also provide 24VDC power at up to 3Amps combined. This is
typically enough power for up to 32 sensors, any associated input modules, and up to 4 alarm modules.
(Alarms are controlled by Detcon’s RL-4 Modules. For more than 32 sensors, an additional power supply
mounted in a separate enclosure is available.) An optional third port is available for use with remote monitors
or displays. The Modbus™ interface is used to communicate directly with Modbus™ capable sensors and
Detcon’s I/O modules. The I/O modules are individually addressable and operate on 11.5-30VDC.
NOTE: The power supply for the Model MCX-32 controller can power up to a maximum of
32 sensors and any associated I/O modules even though the controller is capable of
communicating with up to 64 devices.
An additional power supply will be required if
powering more than 32 sensors.