2 measurement jumpers, Datalogger programming, 1 crbasic programming – Campbell Scientific SDM-SW8A 8-Channel Switch Closure Input Module User Manual

Page 10: 1 sdmsw8a instruction

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SDM-SW8A Switch Closure Input Module

5.2 Measurement Jumpers

Near each input channel is a jumper triplet used to configure the channel for
the measurement type. The SDM-SW8A is shipped from the factory with each
channel configured for DC Voltage pulse. An example of each configuration
is illustrated in Figure 2. Table 4 shows jumper pins and the corresponding
measurement type.

TABLE 4. Measurement Jumpers

Measurement Type

Pins
Jumpered

SPDT Switch Closure

1 and 6

SPST Switch Cl. or Open Coll.

2 and 5

Voltage Pulse

3 and 4

6. Datalogger Programming

The datalogger is programmed using either CRBasic or Edlog. Dataloggers
that use CRBasic include our CR800, CR850, CR1000, CR3000, and CR5000.
Dataloggers that use Edlog include our CR7, CR10(X), CR23X, and 21X.
Both CRBasic and Edlog are provided in PC400 and LoggerNet datalogger
support software.

6.1 CRBasic Programming

6.1.1 SDMSW8A Instruction

The SDMSW8A instruction is used to control the SDM-SW8A Eight-Channel
Switch Closure module, and store the results of its measurements to a variable
array.

Parameter
& Data Type

Enter

Dest
Variable or

Array

The variable in which to store the results of the SW8A measurement. The
variable array for this parameter must be dimensioned to the number of
Reps.

Reps
Constant

The number of channels that will be read on the SW8A. If (StartChan
+Reps –1) is greater than 8, measurement will continue on the next
sequential SW8A. In this instance, the addresses of the SDM devices must
be consecutive.

SDMAddress

Constant

The address of the first SW8A with which to communicate. Valid SDM
addresses are 0 through 15. If the SDMTrigger instruction is used in the
program, address 15 should not be used. If the Reps parameter used more
channels than are available on the first SW8A, the datalogger will increment
the SDM address for each subsequent device that it communicates with.

6

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