PT900-12 Monitor/Controller
Rev 2.0
7
OVERVIEW
Pem-Tech model PT950-B is a microprocessor based single channel
monitor that utilizes the latest digital design techniques in
instrumentation. The monitor uses an 8-bit high speed RISC processor
with a highly accurate analog to digital logic. The controller module
receives signals from remote gas transmitters, displays the gas
concentration, generates 4-20mA analog output for recorders and relay
outputs for alarm warning devices. Each control module uses 24VDC
power and supplies power to the remote gas transmitter connected.
Standard features are:
Displays current gas concentration on two (2) Digit Bright LED
display ( 3 digits display for Oxygen deficiency )
Provides a 4-20mA output.
Low, High, & High-High fully programmable alarm relay contacts.
Alarms programmable via switches on the front panel
Sensor Malfunction relay contact.
Visual alarm indicators on the front panel.
Alarm RESET and BYPASS switch.
RS485 Serial Communication for Remote data display
Master Alarm Reset on the main rack assembly to Reset Alarms.
Programmable Relays
Each control module has three (3) programmable relays for Low, High,
and High-High alarms. The alarm relay set points can be programmed
via pushbutton switch provided on the front panel. On the main
termination board of PT900-12 rack system alarm terminals are provided
for each of the control module. A common terminal is also provided for
sensor malfunction (or fault). This terminal is common to the Fail relays
on all the control modules in the system. The terminal can, therefore, be
used as dry contact for a local audible alarm. In addition jumper blocks
are also provided to common all the relays on the control modules in
order to use an auxiliary relays.
For further details refer to section on Programming alarm Relays later in
this manual.
