CR10X Reference Manual
9-16
If the excitation channel is indexed, parameter 4 then becomes an input location.
The excitation voltage must be loaded into the required input location before
Instruction 22 is executed.
If the only requirement is the delay of program execution, the off-time delay
should be used, with the excitation on-time set to zero.
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:
4
Excitation voltage in millivolts
or
Input location for excitation voltage when the excitation
channel is indexed
Input locations altered: 0
Input locations read: 0 or 1
Instruction 23: Burst Measurement
Instruction 23 makes repeated voltage measurements on a series of single-ended or
differential channels, applying excitation if desired. The measurement units are
millivolts before scaling. The measurements saved can be those made immediately
on execution of the instruction or grouped around a specified trigger condition. The
results of the measurements can be stored in Input Storage or the raw A/D data can
be transmitted from the CR10X’s I/O port. The minimum sample time per channel is
1.333ms (i.e. one channel can be sampled at a maximum rate of 750Hz).
If control ports 6, 7 or 8 are used for pulse measurement using the
Pulse Count Instruction (P3),
no counts will be measured
during the
execution of the Burst Measurement Instruction (P23).
Measurement
The voltage measurement must use the fast integration time of 250µs (25µs on the
2.5V range). Differential measurements are made with a single integration. The
noise level on a fast single-ended measurement or a differential measurement with
one integration is 3µV RMS. Thus, only the 25mV 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 desired, enter 0 for parameter 9.
Three options are available for the first digit in parameter 4:
0
-
Trigger on first measurement channel.
1
-
Trigger on control port 1.
2
-
Trigger on first measurement channel, set 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 multiplier and
offset you specify are not applied before the comparison: the limit must be entered
in units of millivolts. If a digital trigger (where logic low is less than 1.5V and
logic high is between 3.5V and 5V) is used, it must be connected to control port 1.
CAUTION