Fluke PM6685R Outdoor Timer User Manual


 
*OPC reports when operation is com
-
plete, via the Status Subsystem described
on page 6-14.
Rough Trigger
Subsystem
Description
The trigger subsystem is the functional
part of the CNT-8X that controls the start
and stop of measurements. This is the
function that the controller interacts with
when it controls the measurement se-
quence.
A simplified model of the CNT-8X’s trig-
ger subsystem is a state-machine with
four different states. These states are as
follows:
IDLE State
The counter waits for new commands. It is
not measuring
WAIT_FOR_BUS_ARM State
The counter is ready to receive a bus arm
-
ing signal, GET or XTRG.
WAIT_ FOR_MEASUREMENT_TO_
START State
The counter waits for the input signal trig
-
gering to start the measurement or block of
measurements. If the counter uses arming,
it is waiting for the specified arming event.
MEASUREMENT State
The counter measures. It monitors the
hardware and controls the measurement
time. If block measurement mode is used,
(ARM:COUN or TRIG:COUN8³2) the
counter stays in this state until all measure
-
ments inside the block has been made.
Different actions cause the trigger sub
-
system to change between the different
states. The transitions are shown in . The
status is reflected in status byte
:STATus:OPERation:CONDition.
How to Measure Fast
Rough Trigger Subsystem Description 7-3
State:
ID L E
O peration Condition
re g is te r s ta tu s :
256
State:
W A IT F O R B U S A R M
O peration Condition register
status: 320
State:
W A IT F O R E X T A R M a n d /o r
IN P U T T R IG
O peration Condition register
status:
288
State:
MEASURE
O peration Condition
re g is te r s ta tu s :
16
INIT
INIT:CONT ON
or
INIT:CONT OFF
O r all m easurem ent
s
com pleted
Bustrig received or
O FF (im m ediate)
All ARM and TRIG
loops com pleted
(A rm in g rece ive d o r
a rm o ff (im m e d ia te ))
and input trig
Single m easurem ent
re a dy
Figure 7-1 Trigger subsystem states.