Keithley 2002, Getting Started Manual

Page: 76 / 95

Continuous triggering #2
The following example program sets up the Model 2002 to take readings continuously after
an external trigger is received. The trigger rate is set to one reading every 50ms.
'Example program to demonstrate continuous triggering
'at a specified rate
'For QuickBASIC 4.5 and CEC PC488 interface card
'Edit the following line to where the QuickBASIC
'libraries are on your computer
'$INCLUDE: 'c:\qb45\ieeeqb.bi'
'Initialize the CEC interface as address 21
CALL initialize(21, 0)
'Reset controls in INIT, ARM;LAY1, ARM:LAY2, and TRIG subsystems
'and put trigger model in IDLE state
CALL SEND(16, "*rst", status%)
'*RST sets TRIG:SOUR to IMM
CALL SEND(16, "arm:lay2:sour ext", status%)
CALL SEND(16, "trig:coun inf;sour tim;tim .05", status%)
'start everything
CALL SEND(16, "init", status%)
After the Model 2002 receives the
INITiate
command, it stops in
ARM:LAYer2
of the trigger
model, waiting for a pulse on the external trigger jack. After the external trigger signal occurs,
the Model 2002 moves to the
TRIGger
layer. Since
TRIGger:SOURce
is set to
TIMer
, a reading
is triggered immediately, with a subsequent reading every 50ms. Because
TRIGger:COUNt
has
been set to infinity, the trigger model never exits from the
TRIGger
layer.
3-22 IEEE-488 Bus Operation