Analog Outputs; External Digital I/O; Power Up Circuit - Teledyne T400 User Manual

S T
AMPLE
The source of this signal is a thermistor attached to the absorption tube inside the sample
chamber of the optical bench assembly. It measures the temperature of the sample gas in
the chamber. This data is used to during the calculation of the O
UV L
AMP
This thermistor is attached to the UV lamp in the optical bench and reports the current
temperature of that lamp to the CPU as part of the lamp heater control loop.
IZS O
PTION
This thermistor is attached to the UV lamp of the O
reports the current temperature of that lamp to the CPU as part of a control loop that
keeps the lamp temerpature constant.
B T
OX EMPERATURE
A thermistor is attached to the motherboard.
temperature. This information is stored by the CPU and can be viewed in the Dashboard.
6.3.2.4

ANALOG OUTPUTS

The analyzer comes equipped with four analog outputs: A1, A2, A3 and A4. The type of
data and electronic performance of these outputs are configurable by the user (see
Section 2.5.8).
O L
UTPUT
The analog outputs are connected back to the A/D converter through a loop-back circuit.
This permits the voltage outputs to be calibrated by the CPU without need for any
additional tools or fixtures.
6.3.2.5

EXTERNAL DIGITAL I/O

This External Digital I/O performs two functions: status outputs and control inputs.
S O
TATUS
Logic-Level voltages are output through an optically isolated 8-pin connector (labeled
STATUS) located on the rear panel of the analyzer. These outputs convey good/bad and
on/off information about certain analyzer conditions. They can be used to interface with
certain types of programmable devices (See Section 2.3.1.3).
C
ONTROL
By applying +5VDC power supplied from an external source such as a PLC or Data
logger (See Section 2.3.1.5), Zero and Span calibrations can be initiated remotely by
contact closures (labeled CONTROL IN) on the rear panel.
6.3.2.6

POWER UP CIRCUIT

This circuit monitors the +5V power supply during start-up and sets the analog outputs,
external digital I/O ports, and I
instrument software can establish control.
150
S
EMPERATURE ENSOR
T S
EMPERATURE ENSOR
L T S
AMP EMPERATURE
S
ENSOR
-
OOP BACK
UTPUTS
I
NPUTS
2 C circuitry to specific values until the CPU boots and the
Teledyne API – Model T400 O
ENSOR
generator in the IZS option, and
3
It measures the analyzer's internal
Analyzer
3
concentration value.
3
083730400A DCN8130