Stanford Research Systems RGA100, Operating Manual And Programming Reference

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4-6 Rear Panel
SRS Residual Gas Analyzer
LED Functionality
LED's on the rear panel of the ECU provide constant feedback on the status of the
filament, electron multiplier, electronics system, probe and communications, and alert the
user of any detected errors. This section describes in detail the function of each LED.
RS232/DCE/28.8k
+24VDC @ 2.5A
Power Filament Degas ElecMult RS232 Error Leak Burnt
Lock
Lock
STATUS LEDs
ERROR
LEDs
Figure 5 ECU LED’’s
STATUS (Green) LED’’s
Power : The Power LED is turned on whenever the RGA is successfully powered up.
When power is applied to the ECU, a firmware routine automatically checks the external
voltage level and turns on the Power LED if the voltage is within the acceptable range of
24 +/-2 V DC. The same test is performed in units with built-in power modules (Option
02) to check the voltage output of the internal switching power supply. If the check fails,
the red Error LED is turned on instead to indicate the problem.
Note: A check on the external power supply can be performed at any time during
operation using the EP? diagnostic command.
Filament : The Filament LED indicates the presence of electron emission current in the
RGA’’s ionizer. It is turned on when a finite emission current is requested by the user and
during Degas processes. It is turned off when the user requests a null emission current or
when a filament error condition (i.e. overpressure, worn out or burnt filament) is
detected and the filament emission is turned off.
Note: Filament error conditions are easily diagnosed with the help of the Leak and Burnt
LED and the assortment of diagnostic checks built into the firmware and supported by the
RGA Windows program.
Degas : The Degas LED is activated during Filament Degas processes.
The Filament LED is also activated during a Degas.
The ElecMult LED is turned off during a Degas.