Teledyne 9110T - Nitrogen Oxides Analyzer - Manual (Page 344)

Model 9110T NOx Analyzer Principles of Operation
Teledyne Analytical Instruments 344
 For information on setting up the status outputs (see Section 3.3.1.4).
CONTROL INPUTS: By applying 5V DC power to these digital inputs from an external source such as
a PLC or Data logger zero point and span point calibrations can be remotely initiated. .
 For information on setting up the status inputs (see Section 3.3.1.6).
13.3.3.6. Internal Digital I/O
There are several internal digital control signals that are generated by the motherboard under CPU
control and used to control subsystems of the analyzer.
ELECTRICAL TEST CONTROL: When the CPU sets this control signal to high (ON) the electric
test feature (ETEST) is initiated (see Section 8.3).
 The ETEST can be initiated by following the procedure in Section 12.7.12.2, or by setting the
SIGNAL I/O Function ELEC_TEST to ON.
OPTICAL TEST (OTEST) CONTROL: When the CPU sets this control signal to high (ON) the
optical test feature is initiated (see Section 8.3).
 The OTEST can be initiated by following the procedure in 12.7.12.1, or by setting the SIGNAL I/O
Function OPTIC_TEST to ON.
PMT PREAMPLIFIER RANGE CONTROL: The CPU uses this control switch the instrument
between its LOW and HIGH physical ranges (see Section 5.4.1).
 The instrument can be forced into its HIGH physical range setting the SIGNAL I/O function
PREAMP_RANGE_HI to ON.
O
3
GEN STATUS: The CPU uses this control signal to turn the O
3
generator ON/OFF by setting it to
HIGH/LOW respectively. The CPU turns OFF the O
3
generator if there is if there is no or low air flow
to it as measured by the O
3
flow sensor or if the instrument has been turned off for more than 30 minutes.
 The O
3
generator can be manually turned ON/OFF by using the OZONE GENERATOR OVERIDE
feature (See Section 12.7.15.1) or by setting the SIGNAL I/O function O3GEN_STATUS to ON or
OFF.
Note Any I/O signals changed while in the signal I/O menu will remain in effect
ONLY until signal I/O menu is exited.
The analyzer regains control of these signals upon exit and returns them
to their normal value/setting.
13.3.3.7. I 2 C Data Bus
I 2 C is a two-way, clocked, bi-directional digital serial I/O bus that is used widely in commercial and
consumer electronic systems. A transceiver on the Motherboard converts data and control signals from
the PC-104 bus to I
2 C format. The data is then fed to the relay board, optional analog input board and
valve driver board circuitry.