5-10
5 Pulse Concepts and Pulse Generator
Operations
Counter Architecture Overview
*Start source is:
RUN/STOP
key in Internal Modes
External input in External Trigger modes
*TRG command via Serial/GPIB access
**Channels are armed by the RUN button. In single shot and burst modes
channels may be rearmed by pressing the RUN button.
System Timer Functions
The System Timer functions as a non-retriggerable, multi-vibrator pulse
generator. This means that once started, depending on the mode, the timer will
pro-duce pulses continuously. Before pulses can be generated, the timer must
be armed and then receive a start pulse. Arming the counter is done by pressing
the
RUN/STOP
key. With external trigger disabled, the
RUN/STOP
key also
generates the start command for the counter. With external trigger enabled, the
external trigger provides the start pulse. In either case, once started, the counter
operation is determined by the System Mode Generator. Standard modes
include:
Continuous
Once started T
0
pulses are generated continuously.
Single Shot
One T
0
pulse is generated for each start command.
Burst
‘n’ T
0
pulses are generated for each start command.
Duty Cycle
Once started T
0
pulses cycle on and off continuously.