HP Saw E4419B manual Test Descriptions

Power Meter Operation

Self Test

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 E4418B/E4419B Service Guide.

HP E4419B User’s Guide 2-77