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1.1 DATALOGGER PROGRAMS - 1, 2,
3, AND 4 MODES
Data acquisition and processing functions are
controlled by user-entered instructions
contained in program tables. Programming can
be separated into 2 tables, each having its own
user-entered execution interval. A third table is
available for programming subroutines which
may be called by instructions in Tables 1 or 2 or
by a special interrupt. The 1 and 2 Modes
are used to access Tables 1 and 2. The 3
Mode is used to access Subroutine Table 3.
The 4 Mode Table is a table of values used in
the program that someone can change while
the rest of the program is protected. These
values may be used for sensor calibrations or to
select optional sensors. The 4 Table is only
available when a special program created by
EDLOG is loaded in the CR510.
When a program table is first entered, the
display shows the table number in the ID field
and 00 in the data field. Keying an "A" will
advance the editor to the execution interval. If
there is an existing program in the table, keying
an instruction location number prior to "A" will
advance directly to the instruction (e.g., 5 will
advance to the fifth instruction in the table).
1.1.1 EXECUTION INTERVAL
The execution interval is entered in units of
seconds as follows:
1/8 ....31.875 seconds, in multiples of 1/8 (0.125)
32 .....8191 seconds, in multiples of 1 second
Execution of the table is repeated at the rate
determined by this entry. The table will not be
executed if 0 is entered. Entries less than 32
seconds will be rounded to a valid interval if
they are within 1/512 (0.00195) second of a
valid interval, otherwise error E41 will be
displayed. Entries greater than 32 seconds are
rounded to the nearest second.
The sample rate for a CR510 measurement is
the rate at which the measurement instruction
can be executed (i.e., the measurement made,
scaled with the instruction's multiplier and
SECTION 1. FUNCTIONAL MODES
offset, and the result placed in Input Storage).
Additional processing requires extra time. The
throughput rate is the rate at which a
measurement can be made and the resulting
value stored in Final Storage. The maximum
throughput rate for fast single-ended
measurements with standard software is 192
measurements per second (12 measurements
repeated 16 times per second).
If the specified execution interval for a table is
less than the time required to process that
table, the CR510 finishes processing the table
and waits for the next occurrence of the
execution interval before again initiating the
table (i.e., when the execution interval has
elapsed and the table is still executing, that
execution is skipped). Since no advantage is
gained in the rate of execution with this
situation, it should be avoided by specifying an
execution interval adequate for the table
processing time.
NOTE: Whenever the processing time of
the user's program exceeds a table's
execution interval, an error is logged in
memory. The number of overrun errors
can be displayed and reset in the B mode
(Section 1.6) or using the Telecommunica-
tions A command (Section 5.1). An overrun
will also cause decimal points to appear on
both sides of the sixth digit of the CR10KD.
The decimal points will not appear around
the G in LOG if the 0 Mode is entered
before the overrun occurs.
In some cases, the processing time may exceed
the execution interval only when the Output Flag is
set and extra time is consumed by final Output
Processing. This may be acceptable. For
example, suppose it is desired to sample some
phenomena every 0.125 seconds and output
processed data every 10 minutes. The processing
time of the table which does this is less than 0.125
seconds except when output occurs (every 10
minutes). With final output the processing time is
1 second. With the execution interval set at 0.125
seconds, and a one second lag between samples
once every 10 minutes, 8 measurements out of
4800 (.17%) are missed: an acceptable statistical
error for most populations.
1-1
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