Operator`s manual

OV-1
21X MICROLOGGER OVERVIEW
The 21X Micrologger combines precision measurement with processing and control capability in a single
battery operated system.
Campbell Scientific, Inc. provides three documents to aid in understanding and operating the 21X:
1. This Overview
2. The 21X Operator's Manual
3. The 21X Prompt Sheet
This Overview introduces the concepts required to take advantage of the 21X's capabilities. Hands-on
programming examples start in Section OV4. Working with a 21X will help the learning process, so don't
just read the examples, turn on the 21X and do them. If you want to start this minute, go ahead and try
the examples, then come back and read the rest of the Overview.
The sections of the Operator's Manual which should be read to complete a basic understanding of the
21X operation are the Programming Sections 1-3, the portions of the data retrieval Sections 4 and 5
appropriate to the method(s) you are using (see OV5), and Section 14 which covers installation and
maintenance.
Section 6 covers details of serial communications. Sections 7 and 8 contain programming examples.
Sections 9-12 have detailed descriptions of the programming instructions, and Section 13 goes into
detail on the 21X measurement procedures.
The Prompt Sheet is an abbreviated description of the programming instructions. Once familiar with the
21X, it is possible to program it using only the Prompt Sheet as a reference, consulting the manual if
further detail is needed.
Read the Selected Operating Details and Cautionary Notes at the front of the Manual before using the
21X.
OV1. PHYSICAL DESCRIPTION
The 21X Micrologger is shown in Figure OV1-1.
The 21X is powered with 8 alkaline "D" cells
and has only the power switch on the base.
The 21XL is powered with rechargeable lead
acid cells and, in addition to the power switch,
has a charger input plug and an LED which
lights when the charging circuit is active. The
21XL should always be connected to a solar
panel or AC charger. The lead acid batteries
provide backup in event of a power failure but
are permanently damaged if their voltage drops
below 11.76 volts. Campbell Scientific does not
warrant batteries. The battery base is the only
difference between the 21X and the 21XL.
The 16 character keyboard is used to enter
programs, commands and data; these can be
viewed on the 8 digit display (LCD).
FIGURE OV1-1. 21X Micrologger