Agilent Technologies E4419B, User Manual

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2 Power Meter Operation
104 E4419B Power Meter User’s Guide
Test Descriptions
This section specifies what is actually checked by each of the tests. Some of the
tests may only be applicable to one method of invocation (for example, from
the front panel). If this is the case, it is specified in the test description. Most
of the tests have an associated error message which is added to the error
queue if the test fails. The exception to this is the bitmap display test. Refer to
Chapter 4 , “Error Messages”, for details on these error messages.
ROM Checksum
This test calculates the checksum of the firmware and checks it against the
pre-defined checksum stored on the ROM. A pass or a fail result is returned.
RAM
This test carries out a read and write test on the instrument RAM.
RAM Battery
When the firmware is first downloaded, a known value is written into a
battery-backed memory location. This test verifies that the value is still
resident. It returns a pass if the value is still present, otherwise it returns a
fail.
Measurement Assemblies
A measurement assembly is requested to automatically run a self test. This
self test returns either a pass or a fail. A fail can either be produced by the
measurement assembly self test failing or by the measurement assembly not
responding.
Fan
This test confirms that the internal cooling fan is operating.
Serial Interface
Four tests are available for the serial interface: UART configuration, local loop
back, RS232 loop back and RS422 loop back. Both the RS232 and RS422 loop
back tests require a specially wired connector - refer to the
Agilent
E4418B/E4419B Service Guide
.