CR510 OVERVIEW
OV-6
Each instruction in the table requires a finite
time to execute. If the execution interval is less
than the time required to process the table, an
execution interval overrun occurs; the CR510
finishes processing the table and waits for the
next execution interval before initiating the
table. When an overrun occurs, decimal points
are shown on either side of the G on the display
in the LOG mode (∗0). Overruns and table
priority are discussed in Section 1.1.
OV2.2.2. THE OUTPUT INTERVAL
The interval at which output occurs must be an
integer multiple of the execution interval (e.g., a
table cannot have a 10 minute execution
interval and output every 15 minutes).
A single program table can have many different
output intervals and conditions, each with a
unique data set (Output Array). Program
Control Instructions are used to set the Output
Flag. The Output Processing Instructions which
follow the instruction setting the Output Flag
determine the data output and its sequence.
Each additional Output Array is created by
another Program Control Instruction checking a
output condition, followed by Output Processing
Instructions defining the data set to output.
OV2.3 CR510 INSTRUCTION TYPES
Figure OV2.3-1 illustrates the use of three
different instruction types which act on data.
The fourth type, Program Control, is used to
control output times and vary program
execution. Instructions are identified by
numbers.
1. INPUT/OUTPUT INSTRUCTIONS (1-12,
16-29, 105-106, 114, 117, 130, 131, Section
9) control the terminal strip inputs and
outputs (Figure OV1.1-2), storing the results
in Input Storage (destination). Multiplier
and offset parameters allow conversion of
linear signals into engineering units. The
Digital I/O Ports are also addressed with I/O
Instructions.
2. PROCESSING INSTRUCTIONS (30-68,
Section 10) perform numerical operations
on values located in Input Storage and
store the results back in Input Storage.
These instructions can be used to develop
high level algorithms to process
measurements prior to Output Processing.
3. OUTPUT PROCESSING INSTRUCTIONS
(69-82, Section 11) are the only
instructions which store data in Final
Storage. Input Storage values are
processed over time to obtain averages,
maxima, minima, etc. There are two types
of processing done by Output Instructions:
Intermediate and Final.
Intermediate processing normally takes
place each time the instruction is executed.
For example, when the Average Instruction
is executed, it adds the values from the
input locations being averaged to running
totals in Intermediate Storage. It also keeps
track of the number of samples.
Final processing occurs only when the
Output Flag is high (Section 3.7.1). The
Output Processing Instructions check the
Output Flag. If the flag is high, final values
are calculated and output. With the
Average, the totals are divided by the
number of samples and the resulting
averages sent to Final Storage.
Intermediate locations are zeroed and the
process starts over. The Output Flag, Flag
0, is set high by a Program Control
Instruction which must precede the Output
Processing Instructions in the user entered
program.
4. PROGRAM CONTROL INSTRUCTIONS
(83-98, 111, 120-121, Section 12) are used
for logic decisions, conditional statements,
and to send data to peripherals. They can
set flags and ports, compare values or
times, execute loops, call subroutines,
conditionally execute portions of the
program, etc.
