38
1= set low threshold (default / 3)
2= set medium threshold (default)
3= set high threshold (default x 3)
NOTES ON MEASURING ENERGY IN SUPPORT SOFTWARE:
Assuming that the support software is started after the device has been powered up, the correct sequence for
working is as follows:
Set the unit to the lowest energy range that will not result in over-range message.
Establish communications with the device using the $HP command and looking for the response “*[CR]” (see above)
Send the $EF command and check its response. If the response is a "1" (new value available), this indicates that
energy was measured before the software was opened. Assuming that this measurement is not useful to the
application, send the $SE command once to clear the $EF response to "0", and throw away the result. Continue
sending the $EF command until the response is "1" again (this indicates a new pulse has been measured by the
sensor). The recommended period for polling the $EF command is ~100ms, so as not to choke the communications.
If the first response to $EF is "0", continue sending the $EF command until the response is "1". This indicates the
sensor has received a new energy pulse and has finished measuring it.
In either case, once the $EF command returns "1", send the $SE command once. This should return the energy value
of the latest pulse measured by the sensor. Log this measurement for the application; if the response is OVER then
tell the application that this value was ‘over-range’, and that it should change to a higher energy scale before
continuing (or reduce the energy of the laser).
Continue sending the $EF command until seeing "1" again, and then continue as above from.
After changing energy range using $WN command, the sensor takes several seconds to settle before allowing energy
measurements to resume. During this period, the $EF command returns 0.
Use the $ER command to determine if the device is ready to receive the next pulse of energy.
Wavelength Commands:
This section is relevant for all types of sensors.
GENERAL INFORMATION ON WAVELENGTH CONFIGURATION COMMANDS:
Ophir sensors are split into two groups:
Some sensors contain fixed (discrete) laser settings, which are permanently configured inside the sensor. These
settings can be values in “nm” such as “1064” or names of a laser region or laser type, such as “CO2”, “YAG” or
“<0.8” (meaning: “less than 0.8um”). For these sensors, the user can choose one or other of the settings offered,
but cannot change any of the settings. The laser setting can be chosen using $WI and viewed using $AW, and the
default startup setting can be saved using the $HC S command.
Other sensors contain a continuous calibration curve, defined between two wavelength limits for example 200nm
and 1100nm for a photodiode sensor. The user can define up to six “favorite wavelengths”, in nm, at whatever
laser points are convenient. These favorites can be added, deleted or edited by the user using commands $WD,
$WI, $WE, $AW and $WL. A default set of favorites is defined for each sensor in the factory. The favorites can be
permanently saved in the device EEPROM memory using the $HC S command.
Most thermopile sensors use the discrete method, whereas photodiode sensors and some thermopiles use the
continuous method.
If any of the commands supporting the continuous calibration curve are used when the sensor does NOT support a
calibration curve, the following error message will be given: "?NOT USING CALIBRATION CURVE".
If any command is used with an index outside the range 1-6 for a favorite wavelength ($WI, $WD, $WE commands),
it will return an error message "?INDEX NOT IN RANGE"
If the sensor supports a calibration curve, but NO Favorite Wavelengths are defined, then the sensor will default to
use the minimum defined wavelength supported in the calibration curve
All Wavelengths ($AW):
$AW[CR] -> (list of all defined wavelengths or favorite wavelengths defined for this sensor) {Returns the wavelengths
defined for the sensor, see details below.