Thermo 42i, Instruction Manual

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System Description
Electronics
8-6 Model 42
i
Low Source Instruction Manual Thermo Electron Corporation
output range. Negative concentrations can be represented as long as they are
within -5% of full-scale. The zero and span values may be set by the user to
any desired value.
Electronics
All electronics operate from a universal switching supply, which is capable of
auto-sensing the input voltage and working over the entire operating range.
Internal pumps and heaters all operate on 110VAC. An optional
transformer is required if operating on the 210-250VAC or 90-110VAC
ranges.
An on/off switch controls all power to the instrument, and is accessible on
the front panel.
Motherboard
The motherboard contains the main processor, power supplies, a
sub-processor and serves as the communication hub for the instrument. The
motherboard receives operator inputs from the front panel mounted
function key panel and/or over I/O connections on the rear panel and sends
commands to the other boards to control the functions of the instrument
and to collect measurement and diagnostic information. The motherboard
outputs instrument status and measurement data to the front-panel
mounted graphics display and to the rear-panel I/O. The motherboard also
contains I/O circuitry and the associated connector to monitor external
digital status lines and to output analog voltages that represent the
measurement data. Connectors located on the motherboard include:
External Connectors External connectors include:
• External Accessory
• RS-232/485 Communications (two connectors)
• Ethernet Communications
• I/O connector with Power Fail Relay, 16 Digital Inputs, and 6 Analog
Voltage Outputs.
Internal Connectors Internal connectors include:
• Function key panel and Display
• Measurement Interface Board Data