Math Operations
Each math operation performs a specific mathematical operation on each
reading and/or stores data on a series of readings. The multimeter can perform
the null, scale, percent, dB, dBm, filter, RMS, or temperature-related math
operations on readings. The statistics and pass/fail math operations do not
alter readings but store information pertaining to readings. This section
describes how to enable and disable math operations and discusses each math
operation in detail.
Real-Time vs.Math operations can be performed real-time or post-process. When a
Post-Processreal-time math operation is enabled, the operation is performed on each
reading immediately after the reading is taken. The result can then be stored
in reading memory or output over the GPIB. When enabled, a post-process
math operation (except STAT and PFAIL) is performed on each reading as
it is removed or copied from reading memory to the display or the GPIB
output buffer. (The readings in memory are not altered by any post-process
math operation.) The STAT or PFAIL post-process math operations are
performed using the readings in memory immediately after executing the
MMATH command. For the statistics operation, results are stored in the
statistics registers. For the pass/fail operation, an out of limit reading sets bit
number 1 in the status register and displays either FAILED HIGH or FAILED
LOW depending on whether the high or low limit was exceeded.
Enabling MathTo enable a math operation, send the MATH command (for real-time) or the
MMATH command (for post-process) followed by the operation parameter
Operations(DB, DBM, FILTER, NULL, PERC, PFAIL, RMS, SCALE, STAT, or one
of the temperature-related parameters; refer to "Measuring Temperature,
later in this section for a listing of the temperature-related parameters). After
enabling a math operation, it remains enabled until you disable it, cycle
power, execute RESET, or execute one of the PRESET commands. For
example, to enable the NULL operation, send:
OUTPUT 722; "MATH NULL" !ENABLES REAL-TIME NULL OPERATION
or
OUTPUT 722; "MMATH NULL" !ENABLES POST-PROCESS NULL OPERATION
Up to two math operations can be enabled at the same time. The operations
are performed on each reading in the order listed in the command. For
example, to enable the NULL and SCALE operations, send:
OUTPUT 722;"MATH NULL, SCALE" !ENABLEs REAL-TIME NULL & SCALE
or
OUTPUT 722;"MMATH NULL, SCALE" !ENABLES POST-PROCESS NULL & SCALE
To disable all enabled math operations, send:
OUTPUT 722;"MATH OFF" !DISABLES ALL REAL-TIME MATH OPERATIONS
or
OUTPUT 722;"MMATH OFF" !DISABLES ALL POST-PROCESS MATH OPERATIONS
Later you can re-enable the operation(s) that were disabled by the MATH
OFF or MMATH OFF command. To re-enable a single math operation (if
two operations were previously enabled, this will enable only the first of
116Chapter 4 Making Measurements |
ACEC
