Campbell Scientific CR5000 Measurement and Control Module - Manual (Page 168)

Section 7. Measurement Instructions
7-42
Parameter
& Data Type Enter
CaptureTrig
Constant,
Variable, or
Expression
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, 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.
SDMSpeed (BitPeriod)
Changes the rate that the CR5000 uses to clock the SDM data. Slowing down
the clock rate may be necessary when long cables lengths are used to connect
the CR5000 and SDM devices.
Parameter
& Data Type Enter
BitPeriod
Constant or
variable
The time per bit, in microseconds.
Initial Setting (default): 30.0 µS
Resolution: 50 µS
Min Setting: 8 µS
Max Setting 3 mS
SDMSpeed(30) gives: 30.0 µS
SDMSpeed(k) gives: bit_rate = INT(k*20) * Resolution
When calculating SDMSpeed(k), the loggers round down to the next higher
bit rate.
SDMTrigger
When SDMTrigger is executed, the CR5000 sends a "measure now" group
trigger to all connected SDM devices. SDM stands for Synchronous Device
for Measurement. SDM devices make measurements independently and send
the results back to the datalogger serially. The SDMTrigger instruction allows
the CR5000 to synchronize when the measurements are made. Subsequent
Instructions communicate with the SDM devices to collect the measurement
results. Not all SDM devices support the group trigger; check the manual on
the device for more information.
SIO4 (Dest, Reps, SDMAddress, Mode, Command, Param1, Param2,
ValuesPerRep, Multiplier, Offset)
The SIO4 instruction is used to control and transmit/retrieve data from a
Campbell Scientific SIO4 Interface (4 Channel Serial Input/Output device).
See the SDM-SIO4 Serial Input Interface manual for operation details.