Omega Engineering OMB-CHARTSCAN 1400, User Manual

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3-14 ChartScan User’s Manual
External TTL BNC Connectors
ChartScan’s rear panel provides two external trigger BNC connectors. The BNC TTL Scan output is used for
synchronizing equipment with ChartScan. ChartScan can be programmed to trigger on a rising or falling TTL level.
Any TTL level signal (> 2.2V = Hi, < 0.8V = Lo) may be used as a trigger pulse. A trigger pulse may also be used
to generate a Service Request. Note that the TTL Out is a LS-TTL compatible output, 0.4 mA sourcing, 8 mA
sinking. When a scan is logged into the acquisition buffer (after the actual scan), the TTL output signal is pulsed for
100 ms. Refer to the following trigger timing diagram.
Signal Conditioning Cards
ChartScan and its expansion chassis can each house a quantity of 4 signal conditioning cards (8 total, for a possible
128 channels). The signal conditioning cards can be varied using any combination of the following 5 types.
•
CSN/14/TC/P Thermocouple and low volts card for units with subminiature-plugs
•
CSN/14/LV/T Low volts card with removable screw terminals
•
CSN/14/LV/B Low volts card with BNCs
•
CSN/14/LV/S Low volts card with safety jacks
•
CSN/14/HV/S High volts card with safety jacks
Each scanning module fits into the metal, shielded chassis. The chassis insulates the cards from noise and maintains
a constant internal temperature.