3-1
Section 3. Instruction Set Basics
The instructions used to program the CR10X are divided into four types: Input/Output (I/O),
Processing, Output Processing and Program Control. I/O Instructions are used to make
measurements and store the readings in input locations or to initiate analogue or digital
control port output. Processing Instructions perform numerical operations using data from
Input Storage locations and place the results back into specified Input Storage locations.
Output Processing Instructions provide a method for generating time- or event-dependent
data summaries from processed sensor readings in specified Input Storage locations.
Program Control Instructions are used to control program execution based on time and/or
conditional tests on input data and to direct output to external devices.
Instructions are identified by a number. There is a fixed number of parameters associated
with each instruction to give the CR10X the information required to execute the instruction.
The set of instructions available in the CR10X is determined by the CR10X Operating System.
3.1 Parameter Data Types
There are three different data types used for instruction parameters: Floating Point
(FP), 4-digit integers (4) and 2-digit integers (2). The parameter data type is
identified in the listings of the instruction parameters in Sections 9-12. Different
data types are used to allow the CR10X to make the most efficient use of its
memory.
Floating Point parameters are used to enter numeric constants for calibrations or
arithmetic operations. While it is only possible to enter five digits
(mag.00001 to +99999.), the internal format has a much greater range
(1x10
-19
to 9x10
18
– see Section 2). Instruction 30 can be used to enter a number
in scientific notation to be loaded into an input location.
3.2 Repetitions
The repetitions parameter in many of the I/O, Processing and Output Processing
Instructions is used to repeat the instruction on a number of sequential input
channels or Input Storage locations. For example, if you have four differential
voltage measurements to make on the same voltage range, wire the inputs to se-
quential channels and enter the Differential Voltage Measurement instruction once
with four repetitions, rather than entering four separate measurement instructions.
The instruction will then make four measurements, starting on the specified
channel number and continuing through the three succeeding differential
channels, with the results being stored in the specified input location and the three
succeeding input locations. Averages for all four measurements can be calculated
by entering the Average instruction with four repetitions.
When several of the same type of measurements are to be made, but the calibra-
tions of the sensors are different, time can be saved by using one measurement
instruction with repetitions. The calibrations can then be applied with a scaling
array (Instruction 53). This is quicker than entering the instruction several times in
order to use a different multiplier and offset because of the setup and calibration
time for each measurement instruction. However, if time is not a constraint,
separate instructions may make the program easier to follow.