RIGOL  Chapter 2 Command System 
2-88    MSO1000Z/DS1000Z Programming Guide 
:LA:TCALibrate 
:LA:TCALibrate <tcal> 
:LA:TCALibrate? 
Set or query the delay calibration time of the digital channels. The default unit is s.   
  When using the oscilloscope for actual measurement, the transmission delay of the 
probe cable may cause relatively larger error (zero offset). Zero offset is defined as 
the offset of the crossing point of the waveform and threshold level line relative to 
the trigger position. Users can set a delay time to calibrate the zero offset of the 
corresponding channel. 
  You can only set <tcal> to a specified value at certain step. If the parameter sent is 
not one of the specified values, the specified value nearest to the value sent will be 
used. The step of this parameter differs in different horizontal timebase (set by 
the :TIMebase[:MAIN]:SCALe command), as shown in the table below.   
Delay Calibration Time Step 
Note: When the horizontal timebase is equal to or greater than 10μs, the delay 
calibration time cannot be adjusted.   
The query returns the delay calibration time in scientifc notation.   
:LA:TCALibrate 0.00000002        /*Set the delay calibration time to 20ns*/ 
:LA:TCALibrate?                            /*The query returns 2.000000e-08*/