Vmetro VBAT-PB, User Manual

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9 VBAT-PB VME bus anomaly trigger
VBAT-PB Switch settings
Arbiter Enable/Disable
Switches S 1-S5, mounted in the right corner of the board may be used to enable
the onboard Bus Arbitration Function on the VBAT if there is no a other arbiter
in the system. The normal position for these switches is in the
Disable position.
Trigger Output Signals
Front panel Trig output
If the VBAT signal is used to trigger the VBT-325, the trigger output on the
front panel (mini-coax) will go low within 100ns after a valid trigger condition
(violation) has been detected. A trigger condition may consist of all the
VMEbus lines, in addition to an external input and the VBAT-PB error-bit.
ERROR output on VBAT
The delay of up to 100ns introduced by the VBT-325, can in many situations be
too long to trigger an external scope properly. Use the ERROR output on the
piggyback itself if you are looking for short temporary VMEbus violations, or
other fast transitions.
The ERROR output will go low as an immediate effect to any VMEbus
violation. Note that this ERROR output is independent of the VBT-325
circuitry.
Individual trigger outputs
Individual trigger outputs for each possible VMEbus violation is available on
the test-point field, TP1 through TP40. Each of these outputs will go low when
the corresponding VMEbus violation occurs.
The individual trigger outputs can be used to trigger an external instrument (as
a scope or a logic analyzer like VMETRO's TIM200-PB 200MHz Timing
Analyzer piggyback module) on one explicit VMEbus violation.
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