Specifications

Appendix A. Glossary
A-9
normal operation, all processing called for by an instruction must be
completed before moving on the next instruction. The maximum
throughput rate for a fast single-ended measurement is approximately 192
measurements per second (12 measurements, repeated 16 times per
second). This rate is possible if the CR23X's self-calibration function is
suspended (this is accomplished by entering Instruction 24 into Program
Table 2 while leaving the Execution Interval 0 so Program Table 2 never
executes).
When the self-calibration function is operating, the maximum throughput
rate for a fast, single-ended measurement is 192 measurements per second
(12 measurements, 16 times per second).
toggle to reverse the current power state.
USR: drive. A portion of CR1000 memory dedicated to the storage of image
or other files.
UPS uninterruptible power supply. A UPS can be constructed for most
datalogger applications using AC line power, an AC/AC or AC/DC wall
adapter, a charge controller, and a rechargeable battery.
variable A packet of CR1000 memory given an alpha-numeric name, which
holds a potentially changing number or string.
VAC Volts Alternating Current. Mains or grid power is high-level VAC,
usually 110 VAC or 220 VAC at a fixed frequency of 50 Hz or 60 Hz.
High-level VAC is used as a primary power source for Campbell
Scientific power supplies. Do not connect high-level VAC directly to the
CR1000. The CR1000 measures varying frequencies of low-level VAC in
the range of ±20 VAC.
VDC Volts Direct Current. The CR1000 operates with a nominal 12 VDC
power supply. It can supply nominal 12 VDC, regulated 5 VDC, and
variable excitation in the ±2.5 VDC range. It measures analog voltage in
the ±5.0 VDC range and pulse voltage in the ±20 VDC range.
volt meter an inexpensive and readily available device useful in
troubleshooting data acquisition system faults.
Volts SI unit for electrical potential.
watch dog timer an error checking system that examines the processor state,
software timers, and program related counters when the datalogger is
running its program. If the processor has bombed or is neglecting
standard system updates or if the counters are outside the limits, the watch
dog timer resets the processor and program execution. Voltage surges and
transients can cause the watch dog timer to reset the processor and
program execution. When the watch dog timer resets the processor and
program execution, an error count will be incremented in the
watchdogtimer entry of the status table. A low number (1 to 10) of watch
dog timer resets is of concern, but normally indicates the user should just
monitor the situation. A large number (>10) of error accumulating over a
short period of time should cause increasing alarm since it indicates a
hardware or software problem may exist. When large numbers of watch
dog timer resets occur, consult with a Campbell Scientific applications
engineer.