Gage CompuScope 14100C, Hardware Manual And Driver Installation Manual

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CompuScope 14100C 127
CompuScope 14100C Trigger Output
A Trigger signal is used to synchronize different parts of a measurement system to the same event.
CompuScope 14100C provides a TTL output on one of the front panel connectors. The rising edge of this
output signifies that a trigger event has been detected on the CompuScope 14100C.
In a Master/Slave configuration, only the Trigger Output of the Master card should be used.
For best results, this output should be terminated with a 50
Ω
load capable of absorbing 0.5 Watt power.
It should be noted that this output is synchronized to an internal clock, called GCLK, on the CompuScope
14100C. This clock is not the same as the sampling clock.
The relationship between GCLK and sampling clock must be understood in order to take full advantage of this
powerful feature.
Single channel mode
In single channel mode, GCLK is always one-half the frequency of the sampling clock. Consequently, if the
trigger event is asynchronous to the sampling clock, Trigger Out signal will only be activated after one of the two
subsequent rising edges of the sampling clock.
Figure 76: Trigger Out in single channel mode
Dual channel mode
In dual channel mode, GCLK is exactly the same frequency as the sampling clock. Consequently, if the trigger
event is asynchronous to the sampling clock, Trigger Out signal will only be activated after the subsequent rising
edge of the sampling clock.
Figure 77: Trigger Out in dual channel mode
Finally, note that there is no output short protection on this signal, so care should be taken in not interfacing it to
any output, be it Ground or any other voltage.