INFICON STM-1 Thin Film Deposition Monitor - Manual (Page 8)

Configuration parameters, Min/Max/Default values:
Record#
(dec/hex/ascii)
Name Type Minimum (dec) Maximum (dec) Default (dec)
65/41/A SessId Uchar 0 255 0
66/42/B Fq Double 1,950,000 (Hz) 10,050,000 (Hz) 6,050,000 (Hz)
67/43/C Fm Double 1,950,000 (Hz) 10,050,000 (Hz) 5,000,000 (Hz)
68/44/D Density Double 0.01 gm/cc 100 gm/cc 1 gm/cc
69/45/E Zratio Double 0.1 10 1
70/46/F Tooling Double 0.1 10 1
71/47/G RateReq Double 0 A/sec 1000 A/sec 1 A/sec
72/48/H QlvlTrip Uchar 0 9 0
73/49/I SlvlTrip Uchar 0 9 0
74/4A/J Chmods Xmods_class 0 255 0
Xmods_class description (single byte record):
Bit D7
Bit D6 Bit D5 Bit D4 D3 D2 D1 D0
X X X X X X HALT_ERROR X
When HALT_ERROR = 1 and an error occurs (XtalStat is non-zero) then none of the run time data is computed, and ALL
records in the run time data group (except CfgPrmSSID) remain unchanged until the error status is cleared (see XtalOP_class).
This allows a view of the last measurement that caused an xtal fail. This is also useful if the master system does not want to see
every measurement, but check the status of the system once in a while, and does not want to miss process glitches. When
HALT_ERROR = 0, then XtalStat is cleared to no error at the beginning of each new measurement cycle, and the measurement
cycle continues normally.
Note 2.2: Updates to this group are not “live”, meaning updates to this table are not sent to the measurement engine logic
until commanded to do so (committed), and therefore will have no effect on measurements until committed. Queries of
these records return the last update value, not necessarily the value the measurement engine is using. Functions in the
utilities section allows for commits of these parameters, and rollbacks (which fill these records with the data the
measurement engine is using). All updates to all configuration parameter records performed between a commit command
and a rollback command are lost. In summary: Commits send all configuration parameters to the measurement engine,
and rollbacks take all the current data the measurement engine is using and overwrites all the configuration parameter
records. Also, if both a commit and rollback are requested, rollbacks are done first, and therefore the effect of the commit
is lost. Records cannot be queried or updated while a rollback is pending, and records cannot be updated while a commit
is pending. See the description of CPY_CFG_OP_class and notes 2.10 and 2.11 in the Utilities Group for more info on the
use of the CH1_CPY field.
Note 2.3: Changes to Tooling, Density, Z-Ratio, Fq, etc are NOT back-computed into XtalThick. Whenever these are changed,
the measurement engine re-computes all internal constants and uses the last frequency value as a point. The next measurement
therefore will have a correct point to determine rate, which is always accumulated into XtalThick.
Note 2.4: Although any numbers (between 2-10MHZ) can be used for Fq and Fm, the difference (Fq-Fm) should be less than Fq
/ 2. If the frequency shift (measured frequency, RawFreq – Fq) is greater than (Fq / 2), the thickness calculation formula will not
work properly because of the nature of the Z-Ratio adjustment function. This would result in faulty thickness and rate numbers.
Note 2.5: Fq (crystal start frequency) is the frequency the crystal oscillates when uncoated. This is a property of the crystal.
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