Operator`s manual

SECTION 9. INPUT/OUTPUT INSTRUCTIONS
9-9
*** 22 EXCITATION WITH DELAY ***
FUNCTION
This instruction is used in conjunction with
others for measuring a response to a timed
excitation using the switched analog outputs. It
sets the selected excitation output to a specific
value, waits for the specified time, then turns off
the excitation and waits an additional specified
time before continuing on to the next instruction
in the program table. The excitation on time can
be set to zero and the off time delay can be
used if the only requirement is the delay of
program execution.
PARAM. DATA
NUMBER TYPE DESCRIPTION
01: 2 Excitation channel
number
02: 4 Delay time in hundredths
of a second that
excitation is on
03: 4 Delay time in hundredths
of a second after
excitation is turned off
04: FP Excitation voltage in
millivolts
Input locations altered: 0
*** 23 BURST MEASUREMENT ***
FUNCTION
Instruction 23 will repeatedly make a voltage
measurement on a series of single-ended or
differential channels, applying excitation if
desired. The measurement units are millivolts
prior to scaling. The measurements saved can
be those made immediately upon execution of
the instruction or grouped around a specified
trigger condition. The results of the
measurements may be stored in Input Storage
or the raw A/D data can be sent out the serial
port. The minimum sample time per channel is
970µs (i.e., one channel can be sampled at a
maximum rate of 1030 Hz).
MEASUREMENT
The voltage measurement must use the fast
integration time of 250µs. Differential
measurements are made with a single
integration. The noise level on a fast single-
ended or a differential measurement with 1
integration is 3µV RMS. Thus, only the 50mV
and greater voltage ranges are practical (range
codes 13-15).
Excitation is always supplied from excitation
channel 1. The excitation voltage in millivolts is
entered in Parameter 9. If excitation is not
needed, enter 0 for Parameter 9.
TRIGGER
Measurements may be triggered either by the
value of the measurement on the first channel
being measured or by an external digital trigger.
Three options are available. Only one trigger
can be used.
Three options are available for the first digit in
Parameter 4.
0 - Trigger on the first measurement
channel.
1 - Digital trigger on single-ended channel
one (1H).
2 - Trigger on the first measurement
channel, set Digital control port high
when trigger is met and low when
measurements have finished.
When triggering on options 0 or 2, the
measurement on the first specified channel
(Parameter 3) is compared to the limit specified
in Parameter 8.
The user's multiplier and offset are not
applied before the comparison: the limit
must be entered in millivolts. If a digital
trigger (CMOS levels, low < 1.5V, high > 3.5V) is
used, it must be input into single-ended Channel
1 (1H). The digital trigger condition is checked
at the start of each scan.
Five trigger options are available and are
selected by the number entered as the second
digit in Parameter 4: 0 - trigger immediately,
start saving or sending data with the first
measurement made; 1 - trigger if the
measurement is greater than the limit entered or
if the digital trigger is high; 2 - trigger if the
measurement is less than the limit or if the
digital trigger is low; 3 - trigger on rising edge;
i.e., when the measurement goes from below to
above the limit or when the digital trigger goes
from low to high; 4 - trigger on falling edge; i.e.,