Specifications

Touch Controllers Reference Guide54
Frequency Adjust
Note:
MicroTouch provides this command for compatibility with older touchscreen
controllers. To ensure compatibility with all existing and future MicroTouch controllers,
do not use this command when developing your touch drivers and applications.
Syntax: <SOH><Ctrl C>Fnn<CR>
where:
nn = Two ASCII characters that define the frequency setting.
Refer to Table 10 for values.
Description: Lets you change the operating frequency of the sensor drive signal
(DRVOUT) that is fed from the controller to the sensor and drives the
sensor output. You may change the signal frequency to help eliminate
erratic or jittery cursor movement due to electrical interference.
The frequency of the sensor drive signal should not be the same as any
frequency, or second or third harmonics of any frequency, in close
proximity to the sensor. (The CRT scanning signals may cause
interference to the controller if their frequency or harmonics are close
to those of the DRVOUT signal.)
Although the syntax for the Change Frequency command is the same
for the SMT2 and SMT3 series of controllers, the frequency selected
by the command is different for each type of controller. The factory
default setting is also different for each type of controller. Table 10
lists the available frequency settings (in Hz).
Caution:
If your touch application uses the Change Frequency
command with a specified value, be sure to check the frequency if you
replace a SMT2 controller with a SMT3 controller.
!