User`s manual

Counter Architecture Overview
System Timer Functions
The System Timer functions as a non-retriggerable, multi-vibrator pulse genera-
tor. 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
o
pulses are generated continuously.
Single Shot One T
o
pulse is generated for each start command.
Burst n T
o
pulses are generated for each start command.
Duty Cycle Once started T
o
pulses cycle on and off continuously.
The T
o
pulses are distributed to all of the start inputs of the Channel Timers and
Mode Generators
Output
Pulses
Output
MUX
Internal
To Pulse
External
Input
Arm
Start
*
Gate
To
Internal System Timer
and System Mode
Generator
Channel Timers and Channel
Mode Generators
* Start source is: RUN button in Internal Modes
External input in External trigger modes
** Channels are armed by the RUN button. In single shot and burst modes
channells may be rearmed by pressing the RUN a second time.
RUN
Command
**
Start
Gate
Arm
*Start source is: RUN button 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.