Campbell Scientific SDM-CD8S 8 Channel Solid State DC Control Module User Manual
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SDM-CD8S 8 Channel Solid State DC Control Module
CRBasic dataloggers use base 10 when addressing SDM devices.
Edlog programmed dataloggers (e.g., CR10X, CR23X) used
base 4 for addressing (Table 2).
NOTE
CRBasic dataloggers also have the TimedControl instruction which allows a
timed sequence of settings to be managed by the measurement task avoiding
possible processing delays to cause delayed switching (pipeline mode only).
See an example in Section 8.4.
6.2 Datalogger Instructions 104 (CR10/10X, CR23X, 21X, CR7)
and 29 (older CR7s)
The CR10/10X, CR23X, CR7 and 21X use instruction 104 to control the
SDM-CD8S. Instruction 29 is used by older CR7s. The Instruction
descriptions are shown below.
Instruction 104 – SDM-CD8S used with CR10/10X, CR23X,
CR7and 21X dataloggers
Parameter Type Description
1
2
Reps (No. of modules sequentially addressed)
2
2
Starting Address (base 4: 00..33)
3
4
Starting Input Location
Execution Time = 2ms per Rep for the CR10/10X and CR23X
3.5ms per Rep for the 21X and CR7
Instruction 29 – SDM-CD8S used with older CR7s
Parameter Type Description
1
2
Reps (No. of modules sequentially addressed)
2
2
Device (2 = SDM-CD8S)
3
2
Starting Address (base 4: 00..33)
4
2
Card (Excitation card No.)
5
4
Starting Input Location
Execution Time = 150ms to 190ms per Rep
The number of SDM-CD8Ss to be addressed is defined by the Reps
(repetitions) parameter. Each Rep sequentially addresses (00, 01, 02,...32, 33)
SDM-CD8Ss, starting with the address specified in parameter 2 (parameter 3
for Instruction 29).
For each repetition, the 8 ports of the addressed SDM-CD8S are set according
to 16 sequential input locations starting at the input location specified in
parameter 3 (parameter 5 for Instruction 29). Any non-zero value stored in an
input location activates (sets HI 5V) the associated SDM-CD8S port. A value
of zero (0) de-activates the port (sets LO 0V). For example, assuming two
repetitions and a starting input location of 33, outputs 1 to 16 of the first SDM-
CD8S are set according to input locations 33 to 48, and outputs 1 to 16 of the
second SDM-CD8S are set according to input locations 49 to 64.
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