Campbell Scientific CR7 Measurement and Control System - Manual (Page 9)

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SELECTED OPERATING DETAILS
The channel numbering on the Analog Input
Card refers to differential measurements. Single
ended measurements assume the HI and LO
side of each differential channel are two
independent single ended channels, e.g., the HI
and LO side of differential channel 2 are single
ended channels 3 and 4 respectively.
When multiple measurements are specified in
one measurement instruction (through use of
the "Repetitions Parameter") the CR7 I/O
Module is capable of sequencing through 500
fast, single-ended measurements per second.
This specification is the MEASUREMENT
SPEED and should not be confused with
throughput which is the rate at which
measurements are made, converted to
engineering units and stored in Final memory.
With the 700X Control Module (6303 CPU
board), the maximum throughput rate for fast,
single-ended measurements is approximately
310 measurements per second (1 second
execution: Instruction 1 entered 4 times, 3 times
with 99 repetitions, once with 11 repetitions).
Data is stored in Final Memory only by Output
Processing Instructions and only when the
Output Flag is set.
The default case for data stored in Final
Memory is low resolution (4 characters). High
resolution values (5 characters) must be
specified through use of Instruction 78. All data
contained in Input Memory is displayed (*6) as
HIGH RESOLUTION (5 characters) but the
default case for all data stored in Final Memory
is LOW RESOLUTION unless high resolution is
specified through use of Instruction 78.
Floating Point Format - The computations
performed in the CR7 use floating point
arithmetic. CSI's 4 byte floating point numbers
contain a 23 bit binary mantissa and a 6 bit
binary exponent. The largest and smallest
numbers that can be stored and processed are
9 x 1018 and 1 x 10-19, respectively.
The computations performed in the CR7 are
done in floating point arithmetic. Internally, the
number is stored and processed as a binary
number with a 23 bit binary mantissa and a 6 bit
binary exponent. The largest and smallest
numbers that can be stored and processed are
9 x 1018 and 1 x 10-19 respectively. The size
of the mantissa limits the resolution of the
arithmetic to 1 part in 223 binary (1.3 x 109
decimal).
Time is stored with data in Final Memory only if
specifically requested through use of the Real
Time Instruction 77.
Data in Final Storage can be erased without
altering the program by using the *A Mode to
repartition memory. The simplest method is to
re-enter the current allocation for Input Storage
(32 locations is the default allocation). All
memory can be erased and the CR7 completely
reset by entering 1744 for the number of bytes
left in Program Memory.
On-line (as opposed to a manually initiated
dump) data transfer to peripherals (printer,
storage module, etc.) occurs only if enabled
through use of the *4 Mode or Instruction 96.
Data transfer to cassette tape is no longer
supported.