HP WaterSkis E1412A, WaterSkis E1312A Math Operations CALCulate Subsystem, Null Relative Function

Math Operations (CALCulate Subsystem)

This sections provides more information about using the math functions in the CALCulate command. The math operations and registers used to store mathematical data are controlled using the CALCulate command subsystem. See Chapter 3, “Multimeter Command Reference”. There are two steps to initiating a math operation.

1.Select the desired math function:

CALCulate:FUNCtion AVERageDBDBMLIMitNULL

2.Enable the selected math function by turning the calculate state on:

CALCulate:STATe ON

AVERage Function The AVERage function allows you to store the minimum and the maximum reading from a group of measurements then calculate the average value of all the readings. It also records the number of readings taken since the average function was activated.

•The first reading that the multimeter takes is stored as both the minimum and maximum value following activation of the average function. The minimum value is replaced with any subsequent value that is less. The maximum value is replaced with any subsequent value that is greater.

•The minimum, maximum, average and count are stored in volatile memory. The multimeter clears the values when the average function is turned on, when power is turned off or after the module is reset.

•You use the following commands to activate the average function and query the results from the group of measurements made following activation.

CALCulate:FUNCtion AVERage	Selects the average function.
CALCulate:STATe OFFON	Activates the average function.
Take measurements here.
CALCulate:AVERage:MINimum?	Read the minimum value.
CALCulate:AVERage:MAXimum?	Read the maximum value.
CALCulate:AVERage:AVERage?	Read the average value.
CALCulate:AVERage:COUNt?	Read the number of measurements.

NULL (Relative) Function

A null measurement, also called relative, provides the difference between a stored null value and the input signal. One possible application is in making more accurate two-wire ohms measurements by nulling the test lead resistance.

Result = reading - null value

•Does not apply to the DC-to-DC Ratio measurements.

•The null value is adjustable and you can set it to any value between 0 and ±120% of the highest range, for the present function.

•Clearing the NULL value. The null value is stored in volatile memory; the value is cleared when power is removed, after resetting the multimeter or after a function change.

Chapter 2 HP E1312A/E1412A Multimeter Application Information 41