Campbell 21X User manual

21X MICROLOGGER
OPERATOR'S MANUAL
REVISION: 8/95
CopynlcHT (c) 1994, 1995 CAMPBELL sclENTlFlc, lNc.

WARRANTY AND ASSISTANCE
The 21X MICROI-OGGER is warranted by CAMPBELL SCIENTIFIC, lNC. to be free from defects in
materials and wofkmanship under normal use and seruice for thifty-six (36) months from date of shipment
unless specified {thenrvise. Batteries have no warranty. CAMPBELL SCIENTIFIC, lNC.'s obligation under
this warranty is liririted to repairing or replacing (at CAMPBELL SCIENTIFIC, lNC.'s option) defective
products. The cugtomer shall assume all costs of removing, reinstalling, and shipping defective products
to CAMPBELL S0lENT|FlC, lNC. CAMPBELL SCIENTIFIC, lNC. will return such products by surface
carrier prepaid. {his warranty shall not apply to any CAMPBELL SCIENTIFIC, lNC. products which have
been subjected t{ modification, misuse, neglect, accidents of nature, or shipping damage. This warranty
is in lieu of all othtr warranties, expressed or implied, including warranties of merchantability or fitness for
a particular purp(se. CAMPBELL SCIENTIFIC, lNC. is not liable for special, indirect, incidental, or
consequential dafnages.
Products may nof be returned without prior authorization. To obtain a Returned Materials Authorization
(RMA), contact qAMPBELL SCIENTIFIC, lNC., phone [phone]. After an applications engineer
determines the n{ture of the problem, an RMA number will be issued. Please write this number clearly on
the outside of thN shipping container. CAMPBELL SCIENTIFIC's shipping address is:
CAMPBELL SCIENTIFIC, INC.
FtMA#_
815 West 1800 North
l*ogan, Utah 84321 -1 784
CAMPBELL SCIENTIFIC, lNC. does not accept collect calls.
Non-warranty pr{ducts returned for repair should be accompanied by a purchase order to cover the repair.
GAI\/|PEIELL SiCIEN'rIFIC, INC.
815 W. 1800 N.
Logan, UT 84321-1784
USA
Phone (8O1) 753-2342
FAX (8O1) 7sO-954O
Campbell Scientific Canada Corp.
I 1564 -149th Street
Edmonton, Alberta TsM 1W7
CANADA
Phone (4O3) 454-2505
FAX (4O3) 454-2655
Campbell Scientilic Ltd.
14-2o Field Street
Shepshed, Leics. LEl2 gAL
ENGLAND
Phone [phone]
FAX [phone]O91

21X OPERATOR'S MANUAL
TABLE OF CONTENTS
PAGE
WARRANW AND ASSISTANCE
SELECTED OPERATING DETA1LS............ .......'................ v
CAUTIONARY NOTES............. ...'..... vl
OVERVIEW
OV1. PHYSICAL DESCRIPTION
OV1.1 Arlalog Inputs .'..OV-2
OV1.2 Switched Excitation Outputs...... ........'.'... OV-3
OV1.3 Continuous Analog Outputs ' OV-3
OV1.4 Dibital Control Ports .......... '.. OV-3
OV1.5 PUIse Count lnputs ..'.'..........OV-3
OV1.6 14 Volts and Ground ..."......' OV-3
ov2. MEI/|oRY AND PROGRAMMING CONCEPTS
OV2.1 lniernal Memory '...........'.....'OV-3
OV2.2 2lX Instruction Types... .....'.. OV-s
OV2.3 P{ogram Tables and the Execution and Output Intervals ...-.-....... OV-5
OV3. PROGRAMMING THE 21X
OV3.1 Fdrnctional Modes ......'..'...'..' OV-7
OV3.2 Kbv Definition ................ ....." OV-7
OV3.3 Pfogramming Sequence .....' OV-7
OV3.4 lrlstiuction Format '...........'..' OV-8
OV3.5 Entering a Program '............. OV-8
OV4. PHOGRAMMING EXAMPLES
OV4.1 Shmple Program 1 ................ '.......'...'..... OV-g
OV4.2 ebiting an Existing Program OV-11
OV4.3 Sbmpie Program 2................ oV-12
ovs. DATA RETRIEVAL OPT1ONS............ ov-15
ov6. sPEclFlcATloNs ov-18

2.1
2.2
2.3
TABLE OF CONTENTS
PROGRAMMING
1. FUNCTIONAL MODES
Setting and Displaying the Clock - *5 Mode .................. 1-
Displaying and Altering Input.Mernory or Flags -*6 Mode ............-..1-
Compiling and Logging Data - *0 Mode ........................1
Memory Allocation - *A............. ..................'l
Memory Testing and System Status - *B Mode ............ 1
C Mode - Security.... ................1
*D Mode - Save or Load Program .............. 1-
On-Line Data Transfer - Instruction 96, *4 Mode ..........4-1
Manually lnitiated Data Output - "8 and *9 Modes ........4-2
Cassette Tape Option .............4-4
Storage Module (SM192l716) ................. ......................4-6
Printer Output Formats...... ......4-7
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
4.1
4.2
4.3
4.4
4.5
2. INTERNAL DATA STORAGE
Final Storage Areas, Output Arrays, and Memory Pointers .............2-1
Data Output Format and Range Limits .....,... ................2
Displaying Stored Data on Keyboard/Display - *7 Mode ..................2
3. INSTRUCTION SET BASICS
Parameter Data Types ............3-1
Repetitions. ...........3-1
Entering Negative Numbers .......................3-1
Indexing Input Locations ............... .............3-1
Voltage Range and Overrange Detection .....................3-2
Output Processing. ..................3-2
Use of Flags: Output and Program Control ..................3-3
Program Control Logical Constructions................. ........3-4
Instruction Memory and Execution Time...... .................3-6
Error Codes ..........3-9
DATA R ETRI EVAUCOM M U N ICATIO N
4. EXTERNAL STORAGE PERIPHERALS
5.1
5.2
5. TELECOMMUNICATIONS
6.
6.1
6.2
6.3
6.4
6.5
Telecommunications Commands. ..............5-1
Remote Programming of the 21X............. .....................5-3
9 PIN SERIAL INPUT/OUTPUT
Pin Description.............. ..........6-1
Enabling Peripherals ...............6-2
f nterrupting Data Transferto Storage Peripherals................ ...........6-2
Telecommunications - Modem Peripherals. ..................6-2
Interfacing with Computers, Terminals, and Printers ....6-2

TABLE OF CONTENTS
PROGRAMMING EXAMPLES
REMENT PROGRAMMING EXAMPLES
Voltage - Ll200S Silicon Pyranometer................. ..........7-1
and Sensor with a Common External Power Supply .....7-1
Temperatures Using 21X Reference.............. .........7-2
107 Temperature Probe ..........7-3
207 Temperature and RH Probe... .............7-3
Ademometer with Photochopper Output ....7-4
Tipping Bucket Rain Gauge with Long Leads ...............7-4
100 ohm PRT in 4 Wire Half Bridge. ..........7-5
100 ohm PRT in 3 Wire Half Bridge. ..........7-6
100 ohm PRT in 4 Wire Full Bridge.. .........i......... ..........7-7
Prlessure Transducer - 4 Wire Full Bridge.. ...................7-8
Llsimeter - 6 Wire Full Bridge.. ..................7-9
227 Gypsum Soil Moisture Block ............. 7-10
N$nlinear Thermistor in Half Bridge (CSl Model 101)............ ........7-11
Mtasuring 107 Temperature Probe with 60Hz Rejection.... ..,........7-12
PRObESSING AND PROGRAM CONTROL EXAMPLES
CQmputation of Running Average ..............8-1
Rdinfall Intensity ......................8-2
U$ing Control Ports and Loop to Run AM416 Multiplexer. ...............8-3
SIUB 1 Minute Output lnterval Synched to RealTime.......... ............8-5
SpM-AO4 Analog Output Multiplexer to Strip Chart ......... ............... 8-5
CQnverting 0-360 Wind Direction Output to 0-540 for Strip Chart.......... .............8-7
CQvariance Correlation Programming Example.. ..........8-8
FAst Fourier Transform Examples ........... 8-11
PAGE
7.
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.'to
7.11
7.12
7.13
7.14
7.15
7.16
8.
8.1
8.2
8.3
8.4
8.5
8.6
8.7
8.8
10.
INSTRUCTIONS
9. INPUT/OUTPUT INSTRUCTIONS..... ................... e-1
11. OUTPUT PROCESSING |NSTRUCT|ONS...,............ ......... 11-1
12. PROGRAM CONTROL INSTRUCTIONS .........12-1
MEASUREMENTS
13. 21X MEASUREMENTS
13.1 Fast and Slow Measurement Sequence .. 13-1
13.2 Single-Ended and DifferentialVoltage Measurements............ ....... 13-1
13.3 Tfre Effect of Sensor Lead Length on the Signal Settling Time.......... .............. 13-3
13.4 Tfrermocouple Measurements........... .... 13-10
13.5 Biidge Resistance Measurements.............. .............. 13-15
13.6 Rpsistance Measurements Requiring AC Excitation............. .......'t3-19
ill

TABLE OF CONTENTS
INSTALLATION
14. INSTALLATION AND MAINTENANCE
14.1
14.2
14.3
'14.4
14.5
14.6
14.7
14.8
14.9
14.10
Solar Pane1s................. ......... 1
Direct Battery Connection to the 21X............ .............. 1
Vehicle Power Supply Connections .......... 1
Use of DigitalControl Ports for Switching Relays...,.... ................... 14
Grounding.. .........14
Maintenance................. .........14
Calibration Procedures. ......... 1
APPENDICES
GLOSSARY................ ............A-1
PROM SIGNATURES AND SOFTWARE OPT|ONS............. ...............B-1
BINARY TELECOMMUNICATIONS
Telecommunications Command With Binary Responses. ...............C-1
FinalStorage Format..... ..........C-3
Generation of Signature ..........C-4
ASCII TABLE.... .....................D-1
CHANGING RAM OR PROM CHIPS
Disassembly of 21X...... ........... E-1
Installing New RAM Chips.......... ................ E-1
Changing PROM Chips......... .....................E-2
DOCUMENTATION FOR SPECIAL SOFTWARE............. .................... F-1
A.
B.
c.
c.1
c.2
c.3
D.
E.
E.1
E.2
E.3
F.
LIST OF TABLES.. ....... Lr-1
LIST OF FIGURES ....... LF-1
tv

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I SELECTED OPERATING DETAILS
I
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1. StorinolData - Data is stored in Final PROMs are available which have different
Storag-{ only by Output Processing combinations of instructions. Appendix B
Instruiiions and only when the Output Flag describes the options available and gives
is set. i(Sections OV2 and OV3.3) the signatures of the current PROMS.
3. Data Tians{er - On-line data transfer f rom INSTRUCTIONS
Final Qtorage to peripherals (tape, printer,
Storagp Mo.-dule,'etc.)occurs onty if enabied Case Statement (83 & 93, Section 12)
with Inptruction 96 in the datalogger
prografn or in the *4 Mode. (se-clion +.t) Arc Tangent (66 Section 10)
2. Storing Date and Trme Date and time are
stored in Final Storage ONLY if the Reat
Time lrlrstruclionTT is used. (Section 11)
Final $torage Resolution - All Input Storage
values]are displayed ("6 mode) as high
resolulion with a maximum value ol99999.
Howerier, the default resolution for data
stored in FinalStorage is low resolution,
maxin'lum value of 6999. Results
exceefling 6999 are stored as 6999 unless
InstruOtion 78 is used to store the values in
Final $torage as high resolution values.
(Sections 2.2.1 and 11\
Floatirlrg Point Format - The computations
pedorfned in the 21X use floating point
arithnletic. CSI's 4 byte floating point
numbFrs contain a 23 bit binary mantissa
and a16 bit binary exponent. The largest
and srinallest numbers that can be stored
and piocessed are 9 x 1018 and 1 x 10'1e,
respeptively. (Section 2.2.2)
Erasinrg Final Storage Data in Final Storage
can be erased without altering the program
by repartitioning memory in the'A Mode.
(Section 1.5.2)
ALL memory can be erased and the 21X
completely reset by entering 978 for the
numler of bytes left in Program Memory.
(Section 1.5.2)
The set of instructions available in the 21X
is delermined by the PROM (Programmable
Read Only Memory)that it is equipped with.
9. Significant changes in the current PROM
release (OSX-0.1 , OSX-1 .1 , and OSX'2.1)
include:
Wind Vector (69 replaces 76, Section 1 1)
Serial Output has an option to send a file mark
to a Storage Module (96, Section 12)
Low Pass Filter: on the first execution after
compiling, the input value is used for the filtered
result
Commands to set, toggle and pulse porls are
now available for Program Control Instructions
(Section 12)
Revision 3 of the above PROMS includes the
capability to sense status(O V low, 5 V high) on
the high side of a differentialchannel
(lnstruction 91 , Section 12).
FEATURES
Ports can now be manually toggled from the
keyboard or TERM (PC208 software)
The.B Mode now displays PROM version and
revision, execution overruns, and accumulated
error 8s in addition to signatures.
The capability of transferring programs via
cassette tape is no longer supported in the
standard PROM options.
4.
5.
o.
7.
8.

CAUTIONARY NOTES
2.
Damage will occur to the analog input
circuitry if voltages in excess of r16 V are
applied for a sustained period. Voltages in
excess of t8V will cause errors and
possible overranging on other analog input
channels.
There are frequent references in this
manualto Storage Modules. The Storage
Modules referred to are the SM192 and
SM716. The old SM16 and SM64 Storage
Modules cannot pedorm many of the
functions available with the SM192 and
sM716.
?The sealed lead acid batteries u
21XL are permanently damaged if
discharged below 11.76 V. The cel
rated at a 2.5 Ahr capacitv but
slow discharge even in storage. lt i
advisable to maintain a continuous
on the 21XL battery pack, whether
operation or storage (Section 14).
vl

21 X MICROLOGGER OVERVIEW
The 21X Mi ologger combines precision measurement with processing and control capability in a single
battery oper ted system.
Campbell SQientific, lnc. provides three documents to aid in understanding and operating the 21X:
1. This Overuiew
2. 1 The 21X Operator's Manual
3. I fne 21X Prompt Sheet
i
This Overui$w introduces the concepts required to take advantage of the 21X's capabilities. Hands-on
programmin! examples start in Section OV4. Working with a 21X will help the learning process, so don't
just read tha examples, turn on the 21X and do them. lf you want to staft this minute, go ahead and try
the exampldp, then come back and read the rest of the Overview.
The sectiong of the Operator's Manualwhich should be read to complete a basic understanding of the
appropriate are the Programming Sections 1-3, the portions of the data retrieval Sections 4 and 5
the method(s) you are using (see OVS), and Section 14 which covers installation and
Section 6details of serialcommunications. Sections 7 and I contain programming examples.
Sections 9- have detailed descriptions of the programming instructions, and Section 13 goes into
detailon 2 1 X measurement procedures.
The Sheet is an abbreviated description of the programming instructions. Once familiar with the
21X, it is to program it using only the Prompt Sheet as a reference, consulting the manual if
further is needed.
Read the SQlected Operating Details and Cautionary Notes at the front of the Manual before using the
21X.
OV1. PHYSIDAL DESCRIPTION
The 21X Mifrologger is shown in Figure OV1-1.
The 21X is powered with 8 alkaline "D" cells
and has onlf the power switch on the base.
The 21XL ig powered with rechargeable lead
acid cells add, in addition to the power switch,
has a chargpr input plug and an LED which
lights when fhe charging circuit is active. The
21XL shoulfl always be connected to a solar
panel or AC charger. The lead acid batteries
provide bacfiup in event of a power failure but
are permanpntly damaged if their voltage drops
below 11.74 volts. Campbell Scientific does not
warrant bafleries. The battery base is the only
difference between the 21X and the 21XL.
The 16 chafacter keyboard is used to enter
programs, qommands and data;these can be
viewed on tfie 8 digit display (LCD). FIGURE OV1-1. 21X Micrologger
ov-1

21 X MICROLOGGER OVERVIEW
The 9-pin serial l/O port provides connection to
data storage peripherals, such as the
SM192t16 Storage Module or RC35 Cassette
Recorder, and provides serial communication to
computer or modem devices for data transfer or
remote programming (Section 6). This 9 pin port
does NOT have the same pin configuration as
the 9 pin serial ports currently used on many
personalcomputers. An SC32A is required to
OVl.l ANALOG INPUTS
The terminals in the upper strip are for analog
inputs. The numbering on the terminals refers to
the diflerential channels; i.e., the voltage on the
Hl input is measured with respect to the voltage
on the LOW input. When making single-ended
measurements either the Hl or the LOW channel
may be used independently to measure the
voltage with respect to the 21X ground. Single-
ov-2
interface the 21X to a RS232 serial port
(Section 6).
The panel also contains two terminal strips
which are used for sensor inputs, excitation,
control outputs, etc. Figure OV1-2 shows the
21X panel and the associated programming
instructions.
ended channels are numbered sequentially, e
the Hl and LOW sides of differential channel2
are single-ended channels 3 and 4, respectively
(Section 13.2).
The analog input terminal strip has an insulated
cover to reduce temperature gradients across
the input terminals. The cover is required for
accurate thermocouple measurements (Section
13.4).
FfGURE OVl-z. 21X Wiring Paneland Associated Programming Instructions
SERI L I,/o
Tclccommunlcotlons
Progrom Control Instructlons
96 (Tcpe, Storog€ Module, Printer)
97 Initiotc Telecommunicotions
9E Print Chorocter
Input,/Output
Progrom Cont
91 lf
92 lf
Comqnd
'f2J15C7E
ETCITATION OI'TUTS
Input/Output Instructions
4. Ex-Dcl-Se
5. AC Holf Br
6. Full Br
7. 5W Holf Br
8. Ex-Del-Dlff
9. Full Br-Mcx
11.Temp(107)
12 RH (2o7)
22. Exclt-Del
EEE
tr1 EE
EE
rilE
ANAIOG INPIIIS
Input/Output Instructions
1. Volt (SE)
2. vott (uFF)
4. Ex-Del-Sc
5. AC Holf Br
6. Full Br
7. 5W Holf Br
E. Ex-Del-Dlff
9. Full Br-Mox
11 Temp (107)
12 RH-(2O7)
15. Tcmp-TC SE
14. Temp-TC DIFF
17. Tcmp-Poncl