Plug-in universal microprocessor control circuit – Detcon PI-600 User Manual
Page 4
3.0.2 Universal Microprocessor Control Transmitter Circuit
The control circuit is microprocessor based and is packaged as a universal plug-in f ield replaceable module, facilitating
easy replacement and minimum down time. The universality includes the ability to set it for any range concentration
and for any gas type. These gas and range settings must be consistent with the PID Sensor Head it is mated with.
Circuit functions include a basic sensor pre-amplif ier, on-board power supplies, microprocessor, back lit alpha numeric
display, fault, alarm, and calibration status LED indicators, magnetic programming switches, an RS-485 communication
port and a linear 4-20 mA DC output.
3.0.3 Base Connector Board
The base connector board is mounted in the explosion proof enclosure and includes: the mating connector for the con-
trol circuit, reverse input and secondary transient suppression, input f ilter and lugless terminals for all f ield wiring.
3.0.4 Explosion Proof Enclosure
The transmitter electronics are packaged in a cast metal explosion proof enclosure. The enclosure is f itted with a thread-
ed cover that has a glass lens window. Magnetic program switches located behind the transmitter module face plate are
activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive operator interface
with the sensor. Calibration can be accomplished without removing the cover or declassifying the area. Electrical classi-
f ication is Class I; Groups B, C, D; Division 1 (explosion proof).
PI-600 Toxic Gas Sensors PG.4
detcon inc.
Program Switch #2
FLT
ALM
1
CAL
MicroSafe™ Gas Sensor
HOUSTON, TEXAS
PGM
2
PGM
1
ALM
2
MODEL
PI-600
CONTRAST
Alarm & Cal LEDs
Program Switch #1
Menu Driven Display
Plug-in Universal Microprocessor
Control Circuit
Display Contrast Adjust
UNIVERSAL
TRANSMITTER
PPM
0
VOC
NC
ALARM 1
W
H
T
B
L
K
Y
E
L
B
LU
MA
VDC Power In
NO
NC
NO
NC
NO
N
O
/N
C
C
O
M
N
O
/N
C
C
O
M
N
O
/N
C
C
O
M
FAULT
ALM-2
ALM-1
Alarm Dry Contacts
ALARM 2
FAULT
R1
A
B
A
B
4-20 mA Output
RS-485 In
RS-485 Out
Optional 4-20 mA
Signal Developing Resistor
Use 250 ohm 1/4w
JUMPERS
UN-USED
Jumper Programmable Alarm Outputs
Normally Open or Normally Closed
Sensor
Place un-used alarm programming
jumper tabs here
PID Sensor Head
Transmitter Electronics
in Explosion-Proof housing