ViewSmart 200/2050/2150 Controller User's Manual
Document: UM-1021
Revision Level B
24
Figure 3.4
3.1.3
OPTIONAL BRIDGE SENSOR INPUT BOARD #10-0219
Important!
10-0219 PCB’s may only be installed into motherboard position P1.
The 10-bit 10-0219 Two Channel
Bridge Sensor Input
option shown in Figure 3.5 allows
these popular gas detectors to be connected directly to the ViewSmart 200 without
additional signal conditioning or transmitters. Each channel is equipped with a bridge
amplifier, balance potentiometer, and an adjustable switching regulator for setting the
correct sensor excitation voltage. A 3 position coarse gain jumper allows setting the gain
of the bridge amplifier. Fault supervision circuitry forces the ViewSmart 200 into a
FAULT condition upon sensor failure or removal.
This option may also be configured to accept 4-20mA inputs for mixing a sensor and a
current loop into the same board. Placing either channel’s 2 position SENSOR/4-20mA
jumper (JP3 or JP4) into the 4-20mA position, and installing the associated precision 100
ohm socketed resistor, allows 4-20mA signals to be applied to the mA+ / mA- terminals
(see
Optional 4-20mA notes
in Figure 3.5). 100 ohm resistors are taped to the inside of
the ViewSmart 200 enclosure.
Bridge sensors not mounted to the ViewSmart 200 enclosure at the factory will require
the
Initial Setup
calibration procedure described in section 3.1.4. After performing the
one time only
Initial Setup
all subsequent calibrations are by the ViewSmart 200’s
electronic Cal Mode menus (see section 2.2.5). Sensors mounted locally to the
ViewSmart 200 normally do not require
Initial Setup
since it is performed at the factory.
