Specifications
6-26 Programming the RGA Head
SRS Residual Gas Analyzer
Important: The RGA is free of detected errors as long as the STATUS byte is clear
(no bits set).
Each bit of the STATUS byte reflects the result of a different type of internal check.
Each internal check involves several different tests on a component of the RGA (See the
RGA Troubleshooting Chapter for details). The results of the specific tests are stored in
check-specific error bytes. All error bytes can be queried by the computer, using the
Error Reporting commands, to find out which bits are set.
STATUS Bit Internal Check
(a)
ERROR Byte
(c)
Query
(d)
7 not used N.A. N.A.
6 24V External P/S
(b)
PS_ERR EP?
5 Electrometer
(b)
DET_ERR ED?
4 Quadrupole Mass Filter
(b)
QMF_ERR EQ?
3 Electron Multiplier CEM_ERR EM?
2 not used N.A. N.A.
1 Filament FIL_ERR EF?
0 Communications RS232_ERR EC?
(a) RGA component checked. Each check involves several tests on the component.
(b) Internal checks automatically performed upon a power-on-reset
(c) Error bytes that store the results of the tests for each type of internal check.
(d) The Error Reporting command that queries the error byte.
The Error LED is immediately turned on if any one of the bits 1-7 of STATUS is set. Bit
0 of STATUS reports communications errors and the Error LED is only flashed twice
when the bit is set.
The STATUS Byte should be queried regularly by the programming software (ER?
command.)
Commands that involve hardware control (such as Ionizer Control commands) do
diagnostic checks on the hardware as they are executed. Since the command execution
time can be rather long, the RGA prompts the end of execution by sending back the value
of the STATUS byte to the computer. Always check the STATUS Byte value returned for
possible errors.
If one or more bits of the STATUS byte are found set, the specific error bytes (PS_ERR,
DET_ERR, QMF_ERR, CEM_ERR, FIL_ERR, and RS232_ERR) must be queried
individually to diagnose the problem.
Error diagnosis examples
Example #1:
The RGA is powered up and, after the automatic internal checking is over, the Power