


























   LOG512 DATA LOGGING SOFTWARE PACKAGE      
          and MODEL 66 EXPANSION MODULE














                                           LAWSON LABS, INC.
                                           3239 Phoenixville Pike
                                           Malvern, PA 19355


                                               610 725-8800
                                                    or
                                               800 321-5355






Rev. D













                       TABLE OF CONTENTS







INTRODUCTION                                        Page 2

A.  GETTING STARTED                                 Page 2

B.  SYSTEM CONFIGURATION                            Page 3

      1.  DEFINE DATA POINTS                        Page 3

      2.  DEFINE DATA RUN                           Page 7

      3.  DEFINE PRINTER OUTPUT                     Page 8

      4.  RETURN TO MAIN MENU                       Page 9

C.  OPERATION                                       Page 9

D.  TROUBLESHOOTING                                 Page 10

E.  MODIFYING YOUR SOFTWARE                         Page 11

F.  SPECIFICATIONS                                  Page 11

WARRANTY                                            Page 13



INTRODUCTION

     Lawson Labs LOG512 data logging software is a flexible
general purpose data acquisition package. Up to 512 channels of
analog input are accommodated each with its own label, scaling
factors and high and low alarm limits. The data are displayed on
the screen and can be logged or charted on a printer. 16-channel
high resolution strip chart recorder software is built-in. If
desired, the data can be stored on disk automatically between
scans. Sampling can be done at rates from one scan/day to one
scan/second. Up to 4 Model 66 Expansion Modules can be used. Each
Model 66 can accommodate eight multiplexers or thermocouple
amplifiers. The software, written in BASIC, is not copy-protected
and is fully listable. Your program disk contains LOG512.BAS for
running under the interpreter, and a compiled version called
LOG512.EXE. If control functions are to be added or other changes
made, the interpreted version provides easy access. The compiled
version offers speed. An IBM PC, XT or AT (reg. trademarks) or
compatible with 128K of memory and a Model 140 Analog Interface
or a Model 134 16-bit A/D card are required. Two disk drives are
recommended. An IBM graphics printer or Epson (reg. trademark)
compatible graphics printer is required for the strip chart. IBM
or Epson-compatible printers without graphics capabilities will
suffice if charting is not needed.


A.    GETTING STARTED

     First install the A/D card. Make note of the address
selection switch setting before closing the case. Make 14
connections between the A/D card and the first Model 66. All of
the A/D pins are used except Ground. One of the ground terminals
on the Model 66, labeled G, should be connected both to the guard
on the A/D and to chassis ground at the computer. Shielded cable
is recommended. If additional Model 66s are to be installed,
connect the A, B, C, D, & G terminals to the matching terminals
on the first Model 66. Then connect the +/- 0 terminals to the
+/- 1 terminals on the first Model 66. If a third or fourth
Expansion Module is needed, they connect in the same fashion to
A/D input channels 2 and 3. (Please refer to the separate
interconnection diagram.)

     Now connect any Model 17B Multiplexers or Model 20B or 35B
Amplifiers to the Model 66 Expansion Modules. Up to eight Model
17s, Model 20s or Model 35s can be attached to each Model 66.
Connect up to 8 multiplexer A terminals to digital output 0, B
terminals to digital output 1, C terminals to digital output 2,
and if applicable, D terminals connect to digital output 3 on the
Model 66. Now connect the plus/minus outputs on each multiplexer
or amplifier to a pair of analog input terminals on the Model 66.
You may want to mark each multiplexer with its channel number at
this time. We recommend that you enter the configuration section
of the software before connecting more than one analog input
because ground loops or crossed wires on one channel can, in some
cases, interfere with data at another channel. Once the first
data point is checked out, connect the second analog input, etc.
Once all inputs have been connected, for maximum reliability,
ground all unused inputs.

     Your LOG512 disk is supplied without DOS. (You can add your
DOS to the disk using the SYS command.) The recommended procedure
is as follows:

     1. Format a new disk using your DOS.

     2. Put the LOG512 master disk in drive A and the formatted
        disk in drive B. Make sure you see the "A>" prompt.

     3. Type COPY *.* B:

     The LOG512 software is now on your formatted disk. Use that
disk as your working copy and put the original in a safe place.
If you want to save data on disk you might want to format a data
disk now too. Data and programs can be mixed on the same disk, or
data can be kept on a separate disk.

     If the program disk is in drive B, then to start the
compiled version, Type B:LOG512 from the DOS prompt. The
BRUN30.EXE file is required when starting the compiled LOG512. It
should normally be in the same directory as the LOG512.EXE file.
When the compiled LOG512 version C is started, if the file
BRUN30.EXE file is not in the default directory, you will be
asked for the path specification. To avoid this, make sure that
the LOG512.EXE and BRUN30.EXE files are in the current directory
of the current drive. For the interpreted version, with your
system disk in drive A and the "A>" prompt, type BASIC. Now, if
your working disk is in drive B, type RUN "B:DATALOG" to start
the data logging software. Shortly, the MAIN MENU will be
displayed. It offers a choice of 3 options: GATHER DATA, SYSTEM
CONFIGURATION, or EXIT. Select option 1, SYSTEM CONFIGURATION, to
begin.


B.    SYSTEM CONFIGURATION

     In the course of the system configuration you will be asked
many questions. If you see the blinking cursor (underline symbol)
after a question, you will need to press the RETURN key after
your entry. Questions with Yes or No (Y/N) answers and statements
like PRESS SPACE TO CONTINUE are not accompanied by a cursor and
responses don't need to be followed by a RETURN. First select the
DEFINE DATA POINTS option from the configuration menu.

NOTE:  Pressing Ctrl Break at any time will stop program
execution. No harm will be done to exit via Ctrl Break. However,
using the built-in exit points assures that all files will be
closed and that the printer will be returned to normal operating
mode.


1.    DEFINE DATA POINTS

     You will be asked for the address code of the A/D converter,
ADC. See your A/D card manual. If other special purpose cards are
installed, entering an incorrect switch position may have
surprising consequences. If you supply a Model 140 ADC code and
no Model 140 Analog Interface is installed, or if the switches
are set wrong, you will not be able to continue. Turn off the
computer and correct the situation before proceeding.

     After the switch position has been confirmed, you will see
10 numbered choices and four lettered choices. The numbered
choices comprise the possibilities for the data point's
configuration.

NOTE: The choices are slightly different if a thermocouple
thermometer is connected. The thermocouple configuration
procedure will be described shortly.

     Type the number of each option in turn to familiarize
yourself with them. Random answers in this section can do no harm
and can be readily revised. LOG512 will accept any configuration
parameters which will produce meaningful results. If a value that
you enter is not accepted, try entering a more moderate number.

  1).  INPUT CHANNEL
     Enter the number (0 to 3) of the input channel which is
connected to the source for data point 1. The data point number
reflects only the order in which the data will be gathered and
printed. Input channels can be sampled in any sequence.

  2).  EXTERNAL DEVICE TYPE
     If an external device is connected, enter the appropriate
code. If you select "T" for thermometer, you will be asked for
the K constant of the Model 20 or Model 35 which is connected to
that channel. The configuration changes for thermometry. See
below.

  3).  EXPANSION BOX CHANNEL
       and EXTERNAL DEVICE CHANNEL (if any)
     If an Expansion Module is connected, enter the expansion
channel number for this data point. Then, if a Model 17B
multiplexer or Model 20B or 35B amplifier is attached, enter the
input channel number, otherwise, enter zero. For smoothest flow
when entering a new configuration, first check the channel number
(option 1), then select option 3.
   
  4).  LABEL
     Each data point is given its own label. Labels can be from 1
to 8 characters long. Longer entries will be shortened. If you
use a one- or two-character label, you may want to add several
periods for a clearer display. For example:

      "X . . ."

  5).  UNITS
     The units are from 0 to 5 characters long. Longer entries
will be shortened.

  6).  DECIMAL PLACES TO DISPLAY
     Between 0 and five decimal places can be shown. Select the
appropriate number for the clearest display. Remember that the
maximum number of significant digits is five (16-bit resolution)
and that the formatted reading must fit in an eight-place field
including the sign and decimal point.

  7).  OFFSET FACTOR
     The formatting formula is READING = (COUNTS + OFFSET) *
SCALING. (The symbol "*" indicates multiplication.) Suppose, for
example, you have a 1 to 4 volt signal and you wish to display
the result in millivolts as a number from 0 to 3000. The count at
one volt will be 1000, so an offset factor of -1000 is needed to
obtain a formatted reading of zero. See TABLE 1 for often used
offset and scaling factors. The offset factor can also be used to
replace a hardware zero trim adjustment providing that the "zero"
voltage is within the input range of the A/D card.

  8).  SCALING FACTOR
     The scaling factor is normally between 0.001 and 100. It can
be used as a software gain adjustment, to convert the answer to
the desired units, or as a combination of the two. In the above
example the full scale reading would be 4000 plus an offset of
-1000 equals 3000. To convert that to a reading of 100% of full
scale use 100 = 3000 * SCALING or SCALING = 0.03333. See TABLE 1.

NOTE: If the scaling factor is zero, no formatted reading will be
shown and this data point will be skipped during data gathering.


TABLE 1:  TYPICAL OFFSET & SCALING FACTORS

Signal        Units         Offset        Scaling
-------------------------------------------------
+/-5V         Volts            0           0.001
+/-5V         MV               0           1
+/-2V         %             2000           0.025
0-4V          %                0           0.025
4-20MA*       %             -400           0.0625
4-20MA*       MA            -400           0.01

*assuming a 100 ohm terminating resistor


  FORMATTED READING
     The formatted reading is shown here in the same form as it
will appear on the screen. If the offset factor is zero and the
scaling factor is one then the formatted data will read directly
in millivolts. The formatted reading can be used to confirm that
the hardware is properly connected. A percent sign added in front
of the formatted reading indicates that the reading has
overflowed the allotted number of digits. Reduce the number of
decimal places or scale the reading as a smaller number. If
formatted readings are allowed to overflow their fields during
data gathering, the display and printout may be hard to read.
NOTE: No formatted reading will be displayed if the gain factor
is exactly zero.

  9).  HIGH ALARM LIMIT
    A maximum formatted reading can be specified. If the reading
is above the specified limit, it will be displayed in inverse
characters on the screen and emphasized on the printer log. If
audible alarms are selected, a tone will sound each time an out
of range number is displayed. Entering 0 instead of a limit
disables the alarm for that channel. If a high alarm limit of
zero is desired, enter a small non-zero number like .0001.

  0).  LOW ALARM LIMIT
     The low alarm sets a minimum formatted reading. If the low
limit is exceeded the same actions are taken as for the high
limit.

     If you have a thermocouple thermometer connected to the
input channel, the configuration will be the same except as noted
below.

  1).  INPUT CHANNEL
     For maximum accuracy, thermocouples connected to the same
thermocouple thermometer should be grouped in the sampling
sequence.

  5).  TEMPERATURE SCALE
     Scaling is automatic for readings in C, F or K.

  7).  THERMOCOUPLE TYPE
     Enter the letter designation of the thermocouple connected
to this channel. Types E, J, K, S and T are supported. Different
types can be mixed on the same thermocouple thermometer.  

  8).  GAIN (G factor)
     Enter the G factor for the thermocouple thermometer
connected to the selected input channel. Individual thermocouples
can be calibrated by making slight adjustments in this factor.

  COLD JUNCTION TEMPERATURE
    The cold junction temperature is shown in the selected
temperature scale. The cold junction temperature should be close
to room temperature. If you suspect the cold junction calibration
is in error, place the thermocouple for this channel in a room
temperature bath with an accurate thermometer. If the formatted
reading does not agree with the bath thermometer, select option 2
and adjust the K factor. Increasing the K factor by .01 will
reduce the reading by approximately .1 degree C.

NOTE:  If the cold junction temperature reads as absolute zero,
either there is no thermometer connected to the selected channel,
the thermometer is not powered, or the guard connection is
missing from the A/D card.

  LETTERED OPTIONS

M for menu

     Pressing M returns you to the configuration menu.

N for next

     Pressing N advances you to the next data point in sequence.
If that data point is unassigned, all the factors will be carried
over from the previous point. The data point number is used as
the label and the next input channel is selected. If the channel
is a thermocouple #1, make certain the G and K factors are
entered.

     If you want to start from scratch on the next data point,
use the S, for skip, option (see below). During sampling, all
assigned data points will be sampled and displayed in ascending
order of data point number.

S for skip

     After pressing S, you will be prompted for the data point
number that you wish to skip to. The number must be between 1 and
512.

D for delete this one

     Selecting D will zero all values and erase all labels for
the current data point. Other data points are unchanged. Deleted
data points will not be sampled or displayed during the data
gathering process. If you want to temporarily remove a data point
from the sampling sequence you do not have to delete it and then
re-enter all the parameters. Instead you can change the scaling
factor (or gain) to zero. That causes the data point to be
ignored during the sampling process. When you want to reinstate
the data point, only the scaling (or gain) need be re-entered.

Next select option 2, DEFINE DATA RUN


2.    DEFINE DATA RUN

     First you will be asked if you want to change the sampling
interval. An N (for next) answer will bring on the next question.
After a C (for change) answer you will be asked to supply hours,
minutes, and seconds. The maximum sample interval is 24 hours. If
you enter 0 hours, 0 minutes and 90 seconds it will be translated
to 0 hours, 1 minute and 30 seconds. If you select an interval
which is shorter than the time required for one scan, the
sampling will proceed at the maximum rate. Note that under those
circumstances the sampling intervals will not necessarily be
constant.

     Select now for audible or silent alarms. Selecting audible
alarms causes the computer to beep every time an out-of-limits
channel is sampled. Regardless of alarm status, limits violations
are displayed in inverse numbers.

     LOG512 software is equipped with an autostop feature which
allows sampling to stop after a preprogrammed number of scans. If
you wish to change the autostop status, enter C (for change). 
Then you may enter the number of scans to complete before
execution stops. Enter zero for continuous or manually terminated
sampling.

     Next you may choose between automatic data storage on drive
A, B, C, or D or no automatic data storage. The data will be 
stored in a sequential file. The first file entry will be the
scan number. The next entry will be the time. Next comes one
entry for each of the displayed data points in ascending order.
Subsequent scans follow in the same fashion.

     Variable digital filtering is available. You can select for
between 1 and 255 samples to be averaged for each displayed
point. Select a higher number if the screen updates too quickly
to read the data comfortably.

     After the data collection has been defined, the
configuration menu will reappear. Now, select option 3, DEFINE
PRINTER OUTPUT.

3.    DEFINE PRINTER OUTPUT

    If your system has an IBM graphics printer or an Epson
compatible printer with graphics, then all features are available
to you. The strip chart may or may not work with other printers.
The printer can be off, it can log the data or it can plot up to
16 channels. When the printer is set to log, all the data that
appears on the screen is printed after each scan. If you select
the printer off or printer log option, no further printer
configuration is necessary and you will be returned to the
configuration menu.

CONFIGURING THE STRIPCHART

     Any 16 channels can be chosen for charting. All will be
plotted on the same scale. If channels formatted in different
units are to be plotted on the strip chart, you may need to
change some formatting factors to get a clear presentation. The
baseline can be offset in either the plus or minus direction. The
full scale reading must be a positive number. For example, if
temperatures between -20 and 280 degrees C are to be plotted, the
baseline could be set at -20 degrees C with a full scale reading
of 280. Index marks are placed on the Y axis at intervals. The
maximum  number of index marks is 16. Y axis resolution is 1 part
in 850.

     Index marks are placed every ten scans. Also, each tenth
scan is labeled with the time in hours, minutes and seconds.
Points falling outside the scale limits are not plotted.

     You will be asked for the full scale count, the base line
count, the label and units label for the Y axis, the scale
division interval, and the number of channels to plot. Next, you
supply the data point numbers of the channels to plot. The label
for the selected data point is shown for confirmation. After all
the channels have been assigned you will be returned to the
configuration menu. When you are satisfied with the
configuration, select option 4, RETURN TO MAIN MENU.


4.    RETURN TO MAIN MENU

     After selecting option 4, You will be asked if you want to
save the configuration. If you have made substantial changes to
the configuration you will almost always reply Y (for yes) to the
prompt. If you don't save the configuration, the most recent
version will remain in effect until program execution stops. When
LOG512 is restarted it will begin from the most recently saved
configuration. The first CONFIG file found is loaded. The search
sequence is C, D, A & B. If you want different configurations for
different purposes, make additional copies of the working disk
and configure (and label) them accordingly. If you use more than
one configuration, put a suffix on your data file names to
indicate which configuration applies. If you are saving the
configuration, you will be asked if you want to save it on drive
A, B, C or D. You will normally want to keep the configuration
file on the disk which contains the LOG512 software.

     An alternate to the above guidelines may be preferred if you
are using many different configurations and saving data on disks.
You can use a different data disk for each configuration and save
your configuration on the data disk. Then delete the file named
CONFIG from your working program disk. Now, whenever LOG512 is
RUN, the configuration from the data disk will be loaded.

     Next you will be asked if you want to print the
configuration. It is good practice to have printouts of any
configurations with active files as insurance against disk
failure. A printout will also reveal any data points that may
have been overlooked. For example, if you delete a block of data
points in the middle of a configuration, the higher numbered data
points may be forgotten. If you choose not to print or when the
printout is complete, you will be returned to the MAIN MENU. Some
configurations can be constructed in a few minutes, but some
large systems take much longer to configure. Once you are
satisfied with your configuration, especially if it is of the
second type, you may want to make a backup copy of the disk for
your files.


C.    OPERATION

     The data logging sequence in essence is: 1) scan the inputs
and display the data; 2) save the scaled data on disk if desired;
3) print or chart the data if desired; 4) wait for the next scan.
The data collection process is begun by selecting the GATHER DATA
option and is ended either automatically when the preselected
number of scans has been completed or manually by pressing the
Esc key. Any scan in progress will be finished before the Esc key
will stop the sampling. Pressing CTRL RESET will also stop the
logging process and will put the computer back in BASIC although
using CTRL RESET isn't recommended. Pressing CTRL RESET while a
disk is being written on may cause data loss. The data logging
process is described in detail below.

     Select the GATHER DATA option from the main menu. If the
automatic disk storage is selected you will then be prompted for
a name for the data file or D (for directory). If you give the
name of an existing file, the original file will be lost. If your
data disk is not in the specified drive, put it there at this
time. If the printer is to be used, you will be asked to make
sure it is turned on. If the strip chart mode is selected, the
channel labels and y axis will be printed now.

     The first scan is then started and the results are
displayed. If more than 66 points are defined, the earlier ones
will be overwritten by the latter ones. The scan number and the
time at the beginning of the most recent scan are shown in the
upper left corner of the screen. If the second scan begins
immediately after the first has finished, the sample interval
should be extended, otherwise the sampling rate will vary because
disk and printer functions do not always require the same time.
Pressing Esc during or between scans terminates the sample run.

     If the printer is being used and is taken off line during
data gathering, sampling will stop. A disk error with the
autostore feature active will also stop sampling. When the
problem is corrected a new sampling run should be started. The
most common reason for the premature end of a logging session is
a Disk full error. In some cases, program execution can be
resumed with a CONT command after the problem has been rectified.


D.    TROUBLESHOOTING

     Refer to the troubleshooting and background sections in the
appropriate manuals for help with other hardware.

     If you find the program won't load, first make sure that you
are not trying to read a disk formatted by a higher numbered DOS.
If an empty drive spins when trying to start the software, place
any readable disk in that drive and try again.

     If your program files are inadvertently altered, use your
backup disk or reconfigure the system using a copy of the master
program disk.

     If extra points are displayed during sampling, print your
configuration to identify them.

     If a point is missing from the display, make certain that
the scaling (or gain) factor is not zero.

     If the sampling interval is not constant, the interval
should be lengthened. Disk and printer output does not always
require the same time to complete.

     If the wrong configuration is loaded, there must be a file
named CONFIG on another disk. LOG512 will load the first CONFIG
file it finds. It will look first on the disk in drive B, then C,
D and A in succession.

NOTE: Version C CONFIG files are not compatible with earlier
CONFIG files.

     If you get an "out of memory" message, you either do not
have the 128K minimum memory needed or the switches on the
motherboard are not set to reflect the presence of that memory.

     Contact Lawson Labs at 406 257-5355 for help with stubborn
problems.


E.    MODIFYING YOUR SOFTWARE

     You can add your own routines for control output or other
special functions to the "LOG512.BAS" program. Your routines
should be called by a GOSUB instruction at line 7040. Begin all
your variable names with Z to avoid conflict. The scaled reading
for data point Z is READING(Z). The high alarm, low alarm,
scaling factor, and offset factor for data point Z are at AH(Z),
AL(Z), SC(Z) and OS(Z) respectively. Note that Z is the data
point number, and that data point 1 is not necessarily the first
reading displayed on the screen. If you want to use the optically
isolated output port on the A/D card, use OUT ADC, ZCODE.


F.    SPECIFICATIONS

          LOG512 Data Logging Software Package

          GENERAL

              Configurations from 1 to 512 channels
              Resolution of 15 or 16 bits
              Voltage, current or thermocouple inputs
              Sampling rates from 1/day to 1/second
              Not copy-protected and fully listable BASIC
              Compiled BASIC version also provided

          Input Ranges

              +/- 5 volts or 4 to 20 milliamp current loop
              All inputs are protected against overvoltage

          Thermocouple Inputs

              Up to 24 Thermocouple inputs
              Linearizations for types J, K, T, S & E
              Thermocouple types can be mixed
              Individual thermocouple calibration allowed
              One degree C accuracy
              All inputs are protected against overvoltage

         Displayed Output

              Each channel is labeled; i.e. TEMP 1 319 DEG C
              Individual offset and scaling factors for each
                 channel
              Each channel is rounded to the desired 
                 precision
              High and low alarm limits for each channel
              Audible or silent alarms
              Any channel can be removed from the display
                 output

          Printer Output

              Log format includes time and all data points 
                 with labels
              Strip chart allows up to 16 channels to be 
                 plotted
              Strip chart resolution is 1 part in 850
              Selectable scaling and indexing for strip 
                 chart
              The entire configuration can be printed

          Disk Output

              Automatic data storage between scans if 
                 desired
              The scan #, time and scaled data are stored
              Files are Lotus 1 2 3 (reg. tdmk.) compatible

          System Requirements

              128K IBM PC with one disk drive and one
                 Lawson Labs A/D card minimum
              A second disk drive is strongly recommended
              IBM graphics printer (or Epson-compatible           
                 printer with graphics capabilities needed 
                 for strip charts

Model 66 Expansion Module Specifications

          Multiplexer Section

              8-channel differential analog multiplexer
              Analog inputs protected to 60 volts
              Analog output is buffered

          Digital outputs

              8-bit control/address buss provided
              digital outputs and strobe can drive 8 muxes 
                 or amps
              Logic levels are 6 volt CMOS

          Physical Dimensions

              6.25 X 3.75 X 2 inches

          Wall-mounted power supply requires 115VAC at 5 
              watts




                     LIMITED WARRANTY


     All Lawson Labs, Inc. products are guaranteed against
defects in materials and workmanship for a period of one year
from the date of delivery. Products must be returned to Lawson
Labs for warranty service. Loan units are available during
servicing. Contact Lawson Labs, Inc. at 800 321-5355 for return
authorization before returning anything for service.

     The above warranty is in lieu of all warranties express or
implied. Lawson Labs will not be liable for indirect or
consequential damages caused by any defect in this product. Some
states do not allow the limitation of consequential damages, so
the above exclusion may not apply to you.


Ŀ                           Ŀ
               A Ĵ A                   0 Ŀ
               B Ĵ B          DIGITAL  1 Ŀ 
  A/D Board    C Ĵ C          OUTPUTS  2 Ŀ  
               D Ĵ D                   3 Ŀ   
           GUARD Ĵ GUARD                   Ŀ     
          GROUND  NC         Ĵ GROUND                               Ŀ    Ŀ    Ŀ                  Ŀ
   DIGITAL INPUT Ĵ DIGITAL INPUT*    0 + Ŀ  GND   C B A       G  D C B A      GND   C B A                    GND D C B A 
         CH 0  + Ĵ +  0                - Ŀ                                                       Up to                    
               - Ĵ -                 1 + Ŀ    OUT   Model      OUT   Model      OUT   Model       4 more       OUT   Model 
         CH 1  + Ĵ +  1*     ANALOG    - Ŀ     +  -   20B       +  -   17B       +  -   20B                     +  -   35B  
               - Ĵ -         INPUTS  2 + Ŀ                               
         CH 2  + Ĵ +  2*               - Ŀ                                                                        
               - Ĵ -                   :                                                                         
         CH 3  + Ĵ +  3*             7 +   
               - Ĵ -        Ch 0       - 
                       Model 66                                
                                                                               
                                        
  CHASSIS GROUND  
                                    Ŀ  
                                 Ĵ A                   0  A
                                Ĵ B          DIGITAL  1  B          One to eight
NOTE: Ground all               Ĵ C          OUTPUTS  2  C          Model 20Bs or
      unused input            Ĵ D                   3  D          Model 17Bs or
      channels                        Ĵ GUARD                    GROUND     Model 35Bs
                             Ĵ GROUND                      
                                                             0 + 
                                                               - 
                                                             1 + 
                            Ĵ + 0       ANALOG         NOTE: Ground
                           Ĵ -         INPUTS  2 +    unused inputs
                                                                 -                                   *Tie point only
     One to four                                                 :       
    Model 66s may                                              7 + 
       be used                                       Ch 1        - 
                                                   Model 66              
                                                     (opt)               
                                                  
                                                                           
                                            Ŀ                
                          Ĵ + OUT     A    
                         Ĵ -         B   
                                                Model    C  
                                                 17B     D 
                                                (opt)    G 
                                              






FIGURE 1.    TYPICAL INTERCONNECTION DIAGRAM

