Chapter 6
Interfacing to the Card
6-2
6.1 DLL Functions
In the function descriptions below, “long” indicates a 32 bit integer, “double” indicates a
double precision real. Array parameters require a pointer to the first element of the
array (standard C calling convention).
Note
: These function definitions are for SQM242A.DLL, which supports up to 6
SQM-242 cards and the SAM-242 card. Contact Sigma Instruments for information on
interfacing to the older SQM242.DLL.
Sif142Startup2 (long Mode, long CardStatus (0 to 7))
Loads the DLL and initializes the card. Must be called with Mode=0 before any other
function. The card status parameter is an array that returns card installation status
information
Mode
-1 unloads the DLL, any other value loads the DLL.
CardStatus(0)
DLL and card installation status. Values >900 are errors.
CardStatus (1 to 6) Firmware revision of card 1 to 6. Zero is no card found.
Card Status(7)
Firmware revision of SAM-242 card.
Sif142Init (double Xfmax, double Xfmin, double Xinit, double Period)
Initializes the measurement engine. Should be called before readings are taken.
Xfmax
Maximum crystal frequency (10MHz Max). Any measurement
greater than Xfmax results in a Crystal Failure.
Xfmin
Minimum crystal frequency (1MHz Min). Any measurement less
than Xfmin results in a Crystal Failure.
Xinit
Initial frequency of a new crystal. Usually either 6.00 MHz or 5.00
MHz. Must be between Xfmax and Xfmin.
Period
Sets the period of the measurement system between 0.1 and 2
Seconds.
Sif142Simulate (long Mode)
Sets the operating mode. Normal mode requires SQM-242 card(s), sensors, and a
deposition power supply for proper operation. In simulate mode, no SQM-242 card is
needed. The DLL simulates the frequency readings and power output required for PID
loop control. Note that in this mode the initial sensor frequency is fixed at 5.95MHz and
at least 50% output power is required to start simulating deposition.
Mode
1 turns on simulate mode, 0 turns on normal mode.
