HP (Hewlett-Packard) HP 16555A Weather Radio User Manual


 
Configuration Capabilities
The HP 16554A, 16555A, and 16555D can be configured as a single card,
two-card, or three-card system. The number of data channels ranges from 68
channels using just one card to 204 channels when three cards are installed.
A half-channel acquisition mode is available for timing analyzers which
reduces the channel width by half, but doubles memory depth from
500K-deep to 1M-deep per channel on the HP 16554A, from 1M-deep to
2M-deep per channel on the HP 16555A and from 2M-deep to 4M-deep per
channel on the HP 16555D.
Modules are made of cards cabled together to form a single timebase. A logic
analyzer module may use from one to three cards. All the cards in a module
must have the same model number. Because the clock is common to all
cards in a module, the data is always synchronized. For tightly coupled
measurements involving multiple HP 16554A, 16555A, or 16555D modules,
your analyzer module provides an external reference clock. The reference
clock prevents large data samples from becoming unsynchronized towards
the end of a measurement. Because the internal clock on each logic analyzer
card is accurate to 100 parts per million, in a 2M timing measurement using
two modules, the last sample of each may be separated by as much as 100
times the sample period. The external reference clock prevents this by
having multiple modules share the same clock. There is no limit to how many
modules may share the clock.
See Also "Connecting the External Reference Clock" in chapter 2, Probing, for
information on configuring the external reference clock.
General Information
Configuration Capabilities
1–4