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HP VXI E1432A User Manual

Page 118

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Trigger Lines (TTLTRG)

TTLTRG consist of eight TTL lines on the VXI backplane on connector P2.
They are available to provide synchronization between devices. VXI devices
can use the TTLTRG lines for simple communication with other devices.
For example, a device can wait for a line to go high before taking an action,
or it can assert a line as a signal to another device.

The HP E1432A uses two trigger lines. These can be placed on any two of
the eight TTLTRG lines available on the VXI backplane. The lines are:

q

Sync/Trigger line

q

Free-running clock line

When programmed in a multiple-module configuration, only one of the HP
E1432A modules can provide the clock signal but any of them can trigger.

10 MHz Crystal Clock

Clock
MUX

VXI 10 MHz Clock

24.576 MHz Clock

External Sample

External Trigger

Input Trigger

Source or Tach Trigger

96002 Trigger

10 MHz, Sample 0, none

Sync

Sync

Note: External Sample and External Trigger
inputs are not available on HP E1432A's with
a source option. The External Sample input
is not available on HP E1432A's with a
tachometer option.

Trigger

Trigger

Gate Array

VXI

bus

Sample 1
Sample 2

Sample 3

to

in

put

cir

cuits

Sample 0

(word rate)

PLL

Clock

Oversampled

Generator

Sample 0

Logic

Figure 5-11: Clock/sync diagram

HP E1432A User's Guide

Module Description

5-13

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