Campbell Scientific CR9000X Measurement and Control System - Manual (Page 253)

Section 7. Measurement Instructions
7-29
Parameter
& Data Type Enter SDMINT8 PARAMETERS
For example, 4301 in the second function parameter means to return 3 values: the period for
channel 1, (nothing for channel 2) the time between an edge on channel 2 and an edge on
channel 3, and the time between an edge on channel 1 and an edge on channel 4. The values
are returned in the sequence of the channels, 1 to 16.
Note: the destination array must be dimensioned large enough to hold all the functions
requested.
OutputOpt Code to select one of the five different output options. The Output Option that is selected will
be applied to the data collection for all of the SDM-INT8 channels. The numeric code for
each option is listed below with a brief explanation of each. See the SDM-INT8 manual for
detailed explanations of each option.
Code Result
0: Average of the event data since the last time that the INT8 was interrogated by the
datalogger. If no edges were detected, 0 will be returned for frequency and count
functions, and 99999 will be returned for the other functions. The INT8 ceases to
capture events during communications with the logger, thus some edges may be
lost.
32768 Continuous averaging, which is utilized when input frequencies have a slower
period than the execution interval of the datalogger. If an edge was not detected
for a channel since the last time that the INT8 was polled, then the datalogger will
not update the input location for that channel. The INT8 will capture events even
during communications with the datalogger.
nnnn Averages the input values over "nnnn" milliseconds. The datalogger program is
delayed by this instruction while the INT8 captures and processes the edges for
the specified time duration and sends the results back to the logger. If no edges
were detected, 0 will be returned for frequency and count functions, and 99999
will be returned for the other functions.
-nnnn Instructs the SDM-INT8 to capture all events until "nnnn" edges have occurred on
channel 1, or until the logger addresses the SDM-INT8 with the CaptureTrig
argument true, or until 8000 (storage space limitation) events have been captured.
When the CaptureTrig argument is true, the SDM-INT8 will return up to the last
nnnn events for each of the programmed SDM-INT8 channels, reset its memory
and begin capturing the next nnnn events. The Dest array must be dimensioned
large enough to receive the captured events.
-9999 Causes the INT8 to perform a self memory test. The signature of the SDM-
INT8's PROM is returned to the datalogger.
RESULT CODE DEFINITION
0 Bad ROM
-0 Bad ROM, & bad RAM
Positive integer ROM signature, good RAM
Negative integer ROM signature, bad RAM
CaptureTrig
Constant,Va.r
or Expression
This argument is used when the "Capture All Events" output option is used. When
CaptureTrig is true, the SDM-INT8 will return the last nnnn events.
Mult, Offset
Constant,
Variable,
Array, or
Expression
A multiplier and offset by which to scale the raw results of the measurement. See the
measurement description for the units of the raw result; a multiplier of one and an offset of 0
are necessary to output in the raw units. For example, the TCDiff instruction measures a
thermocouple and outputs temperature in degrees C. A multiplier of 1.8 and an offset of 32
will convert the temperature to degrees F.