63
LT360 Precision Turntable
DLL Programming Manual
■ Class Get (in)
■ Identifier lt_GetInputPolarity
■ Hex Value 0xAD
■ Call LT360LIB_CmdValue(Handle, lt_GetInputPolarity, RtnStr);
■ Returns 'UNIPOLAR' or 'BIPOLAR'
Description
This command returns the mode for the Analog Input Polarity of the LT360.
The returned string value is either UNIPOLAR or BIPOLAR.
This parameter changes how the LT360 interprets the DC voltage received
at the Analog Input connector. When InputPolarity is set to UNIPOLAR, the
LT360 will accept voltages in the range of 0.000 to +3.600 volts. All posi-
tion values are positive. When it is set to BIPOLAR, the range will be 0.000
to ±1.800 volts. Both positive and negative values are used.
Voltages higher than the allowable range for the selected mode are invalid.
The LT360 has a scale factor of 10mV/deg for the analog input. The range
can be either unipolar (0 ... +3.600V) or bipolar (0 ... ±1.800V). The input
impedance of the analog input is 1M Ohm. Although the input is an
unbalanced BNC connector, the actually circuitry is differential. This helps
to reject ground noise.
The input source must be very stable and of low noise. The LT360 has a
resolution of 0.1 degrees and therefore responds to changes of 1mV at the
analog input. When this input is enabled, the LT360 will sample the input
and move to the location as indicated by the voltage. After that move is
completed, it then samples the analog input again and moves to the new
position. Monitoring of the analog input is real time.
If you are not using the analog input, this input must be set OFF. Otherwise
the LT360 will be controlled by any noise received at the input.
2.44 Get Input Polarity