Campbell Scientific SDM-INT8 8-Channel Interval Timer - Manual (Page 14)

SDM-INT8 8 Channel Interval Timer
as a trigger to start making measurements. The Dest parameter must be
dimensioned large enough to receive the captured events.
-9999: Initiates a self memory test of the INT8. A numeric code is returned to
indicate the results of the test.
Code Description
0 Bad ROM
-0 Bad ROM and bad RAM
positive integer: Good ROM (value returned is the ROM signature) and good
RAM
negative integer: Good ROM (value returned is the ROM signature) and bad
RAM
CaptureTrig: This argument is used when the Capture All Events output
option is used. When CaptureTrig is true, the INT8 will return the last nnnn
events.
Mult: The multiplier with which to scale the raw data.
Offset: The offset that is to be applied to the raw data.
This instruction must NOT be placed inside a conditional
statement when running in pipeline mode. NOTE
5.1.2 SDMSpeed Instruction
The SDMSpeed instruction is used to change the bit period that the datalogger
uses to clock the SDM data. Slowing down the clock rate may be necessary
when long cable lengths are used to connect the datalogger and SDM devices.
The syntax of this instruction is as follows:
SDMSpeed ( BitPeriod )
The BitPeriod argument can be an integer or a variable. If the SDMSpeed
instruction is not in the program, a default bit period is used. If 0 is used for
the argument, the minimum allowable bit period is used. Table 1 shows the
default, minimum allowable, and maximum bit period for each of our CRBasic
dataloggers.
TABLE 1. Bit Period Values
Datalogger Default
Bit Period Minimum Allowable
Bit Period Maximum
Bit Period
CR800, CR850 26.04 μsec 8.68 μsec 2.2 msec
CR1000 26.04 μsec 8.68 μsec 2.2 msec
CR3000 26.04 μsec 8.68 μsec 2.2 msec
CR5000 30 μsec 8 μsec 3 msec
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