Operator`s manual

21X MICROLOGGER OVERVIEW
OV-8
OV3.4 INSTRUCTION FORMAT
Instructions are identified by an instruction
number. Each instruction has a number of
parameters that give the 21X the information it
needs to execute the instruction.
The 21X Prompt Sheet has the instruction
numbers in red, with the parameters briefly
listed in columns following the description.
Some parameters are footnoted with further
description under the "Instruction Option Codes"
heading.
For example, Instruction 73 stores the
maximum value that occurred in an Input
Storage Location over the output interval. The
instruction has three parameters (1)
REPetitionS, the number of sequential Input
Storage locations on which to find maxima, (2)
TIME, an option of storing the time of
occurrence with the maximum value, and (3)
LOC the first Input Storage Location operated
on by the Maximum Instruction. The codes for
the TIME parameter are listed in the "Instruction
Option Codes".
The repetitions parameter specifies how many
times an instruction's function is to be repeated.
For example, four 107 thermistor probes, wired
to single-ended channels 1 through 4, are
measured using a single Instruction 11, Temp-
107, with four repetitions. Parameter 2
specifies the input channel of the first thermistor
(channel 1) and parameter 4 specifies the Input
Storage Location in which to store
measurements from the first thermistor. If
Location 5 were used, the temperature of the
thermistor on channel 1 would be stored in Input
Location 5, the temperature from channel 2 in
Input Location 6, etc.
Detailed descriptions of the instructions are
given in Sections 9-12.
OV3.5 ENTERING A PROGRAM
Programs are entered into the 21X in one of
four ways:
1. Keyed in using the 21X keyboard.
2. Loaded from a pre-recorded listing using
the *D Mode. There are 2 types of
storage/input:
a. Stored on disk/sent from computer
(PC208 software TERM and EDLOG).
b. Stored/loaded from SM192/716 Storage
Module
3. Loaded from Storage Module or internal
PROM (special software) upon power-up.
A program is created by keying it directly into
the datalogger as described in the following
Section, or on a PC using the PC208
Datalogger Support Software.
EDLOG and TERM are PC208 Software
programs used to develop and send programs
to the 21X. EDLOG is a prompting editor for
writing and documenting programs for Campbell
Scientific dataloggers. Program files developed
with EDLOG can be downloaded directly to the
21X using TERM. TERM supports
communication via direct wire, telephone, or
Radio Frequency (RF).
Programs on disk can be copied to a Storage
Module with SMCOM. Using the *D Mode to
save or load a program from a Storage Module
is described in Section 1.8.
If the SM192/716 Storage Module is connected
when the 21X is powered-up the 21X will
automatically load program number 8, provided
that a program 8 is loaded in the Storage
Module (Section 1.8).
It is also possible (with special software) to
create a PROM (Programmable Read Only
Memory) that contains a datalogger program.
With this PROM installed in the datalogger, the
program will automatically be loaded and run
when the datalogger is powered-up, requiring
only that the clock be set.
OV4. PROGRAMMING EXAMPLES
We will start with a simple programming
example. There is a brief explanation of each
step to help you follow the logic. When the
example uses an instruction, find it on the
Prompt Sheet and follow through the description
of the parameters. Using the Prompt Sheet
while going through these examples will help
you become familiar with its format. Sections 9-
12 have more detailed descriptions of the
instructions.