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Chapter 1
Basic Testing
Identifying test requirements
Data Communications and Diphase Testing Manual
January 2016
21148872, Rev. 002
Page 5
Interface
Determine which data communications interface you are testing, and the PIM and cable
you’ll need to connect to the interface. The instrument currently supports a PIM that
allow you to test RS-232/V.24, EIA-530, EIA-530A, MIL-188c, X.21, V.35, RS-449/V.36,
and MIL-188-114 interfaces, and a PIM that allows you to conduct Diphase testing.
Use the
Interface
button on the Main screen to specify the interface you are currently
testing.
Equipment emulation mode
Determine whether you need the instrument to emulate a data communications equip-
ment (DCE) device, or a data terminal equipment (DTE) device. The emulation mode
you select dictates which signal leads you can control on the circuit and the transmit
and receive clocks you can select when you configure your test.
•
If the instrument is establishing a link directly to a DCE you should configure the
instrument to emulate a DTE.
•
If the instrument is establishing a link directly to a DTE you should configure the
instrument to emulate a DCE.
•
A network element’s link partner’s emulation mode always dictates the emulation
mode for the element. A DTE link partner communicates with elements in DCE
mode; a DCE link partner communicates with elements in DTE mode.
Signal mode
If you are testing an EIA-530/EIA-530A, RS-449/V.36, or MIL-188-114 interface, deter-
mine whether the circuit under test uses balanced amplifiers. If so, you must select a
balanced circuit when you configure your test. You can also optionally specify the input
termination for the instrument’s receiver in ohms on the Interface setup tab.
Timing mode
If you are testing an RS-232/V.24 interface, determine whether the device you will
connect the instrument to uses asynchronous or synchronous timing. When you
configure your test, specify the same mode for the instrument. Many of the settings
used to configure your test will vary depending on whether they apply for synchronous
or asynchronous timing.
Data rate
If you are using the instrument to emulate a DCE, or a DTE with recovered timing,
determine the data rate for the device you will connect to. You must configure the instru-
ment to use the same rate.