Measurement Computing Data Acquisition Systems rev.10.4 - Manual (Page 364)

G-6 Glossary
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Programmer’s Manual
Pointer
The address of the value [or variable quantity] in memory, rather than the actual value or variable itself.
Post-trigger
The data [or state of an acquisition] after the occurrence of the trigger event. If referencing data, the post-trigger
data was the data collected after or during the occurrence of the trigger event. If referencing the acquisition state,
then the device has been triggered.
Pre-trigger
The data or state of an acquisition before the occurrence of the trigger event. If referencing data, the pre-trigger data
was the data collected before the trigger event occurred. If referencing the acquisition state, then the device has
currently not been triggered.
PSHORT
A pointer to a 16-bit signed integer (2 bytes) or array of 16-bit signed integer quantities, ranging from
–32,768 to +32,768. This parameter type should be passed by reference according to the dictates of the
programming language used.
PWORD
A pointer to a 16-bit unsigned integer (2 bytes) or array of 16-bit unsigned integer quantities, ranging
from 0 to 65,535. This parameter type should be passed by reference according to the dictates of the programming
language used.
Rising/Positive Edge
An event in which an input signal has reached [or exceeded] a particular level with a positive slope. This normally
refers to a trigger or start event, or the manner in which a counter detects an event that should be counted.
RTD (Resistance Temperature Detector)
An RTD is a 3 or 4 wire transducer that uses resistance to produce 3 voltage inputs that can then be converted to a
temperature, using known transfer functions in software. Both 3 and 4 wire configurations may be used. For
programming, this term generally refers to a channel (using a DBK9) that has an RTD connected to it.
RTD (Resistance Temperature Detector) channel
Describes an RTD channel on a DBK9 temperature expansion module.
Sample
The value of a signal on an input or output channel at an instant in time.
Scan
Either the channels that are configured for acquisition (see Channel Scan Group), or the data retrieved during the
acquisition for a single channel scan group.
Sequencer
A programmable device that manages input channels and channel-specific settings for devices that multiplex their
input channels (MUX).
SHORT
A 16-bit signed integer (2 bytes) quantity that can range from –32,768 to +32,768. This parameter type should be
passed by value according to the dictates of the programming language used.
Simultaneous Sample and Hold (SSH)
An operation that gathers samples from multiple channels at the same instant and holds these values until all are
sequentially converted to digital values.
Single-Ended Mode (SE)
The single-ended mode measures a voltage between a signal line and a common reference that may be shared with
other channels (compare with Differential Mode).