Sentry Industries 5000 User Manual

 

The Sentry 5000 is a fixed installation gas monitoring 
system designed for continuous operation in open or 
confined areas.  The system is comprised of a controller 
and up to eight sensor modules.  The sensor modules are 
supplied for detection of combustible gas, oxygen 
deficiency or various toxic gases and can be mixed within 
one system as required. 

The Sentry controller is a microprocessor computer which 
performs functions including management of the sensor 
modules, management of alarm relays and interface with 
the user via the front panel which includes a concentration 
display, an alphanumeric display, keypad and status 
indicators.  The microprocessor functions are permanently 
installed in the controller.  They cannot be changed or 
damaged by the user and will not be altered by loss of 
power. 

Configuration variables, such as alarm levels, can be 
changed via a simple keypad sequence.  Information 
provided to the controller in this manner is retained even 
when the power is interrupted.  This information can be 
protected by a "user code" to avoid unauthorized 
modification. 

Sentry continually scans all modules for alarm conditions.  
No sequence of key presses can prevent the scanning 
except specific actions during calibration or deliberate 
disabling of the sensor module. 

The Sentry controller is provided in a rack or panel mount 
version for control rooms, an environmental enclosure for 
outdoor, stand alone applications, or other packages for 
specialty applications. 

Various factory installed firmware enhancements are 
available for the Sentry controller.  These are selected at 
the time of purchase or subsequent upgrade.  The 
enhancements, which are described in detail in the 
appropriate sections of this manual, include: 

− 

Addition of printer output firmware for models 
5000-04 or 5000-02.  Printer output is standard 
on model 5000-08. 

− 

Replace printer output firmware with 

 

data address protocol for host computer or DCS 
interface.  

 is an industry standard 

communication protocol which allows bi-
directional communication via the controller RS-
232C serial port. 

− 

High Alarm Acknowledge function for alarm 
reset. 

− 

Low Alarm Acknowledge function for alarm 
reset 

− 

Emergency Alarm function adds a third alarm 
level. 

− 

Zone and Voting assignment of individual alarm 
relays. 

− 

Analog Output software driver for use with 
Model 4314-01 output module. 

− 

Custom default Gas Tags and Engineering Units 
Tags for up to eight input devices. 

− 

Custom default Module Tags for up to eight 
module addresses. 

− 

Configure alarm relays to be normally energized 
in the safe condition. 

Each sensor module ("module") is labeled internally to 
identify the type of gas it is designed to detect.  For  each 
gas group, the sensor and the electronics board in the 
explosion proof housing is different.  During installation, 
switches in the electronics are set by the user to give the 
module an address  (module number) to  make it unique 
from others in the same system.  Sentry then 
"communicates" with each module to determine its 
number, the type of gas it detects, the gas concentration 
and other information. 

Inside the module housing is an electronic assembly 
consisting of two printed circuit board assemblies mounted 
under a metal top plate.  The address switches and 
adjustment potentiometers are accessible through the plate 
and electrical test points (test lead jacks) are installed in 
the plate.  Connectors  for wiring from the controller and 
the sensor are located on the bottom of the electronic 
assembly.  The sensor is installed in one hub of the 
enclosure.