MODEL 102 4-channel Simultaneous Sampling A/D Converter

			LAWSON LABS, INC.
			3217 Phoenixville Pike
			Malvern, PA, 19355

			610 725-8800 or
			800 321-5355

          Rev. A
			TABLE OF CONTENTS

	INTRODUCTION					Page  2

	1.  INSTALLATION					Page  3

	2.  OPERATION

		1. Read digital inputs			Page  5
		2. Set digital outputs			Page  5
		3. Mode settings				Page  5
		4. Scanning Sequence			Page  6
		5. Single Scan Operation		Page  6
		6. Setting Clock Rate			Page  7
		7. Viewing Buffer Contents		Page  7
		8. Capture N scans			Page  7
		9. Pre/post triggering			Page  8
		10. Counters				Page  8
		11. Stream to Disk			Page  9
		12. Graphics				Page  9
		13. Files					Page 10
	
	3.  PROGRAMMING					Page 13

	4.  TROUBLESHOOTING				Page 14

	5.  INTERNAL ADJUSTMENTS			Page 16
	
	6.  SPECIFICATIONS				Page 17

	7.  WARRANTY					Page 18

								Page 2

				        INTRODUCTION

		    The Lawson Labs, Inc. Model 102 is a 90 KHZ 4-channel
		simultaneous sampling 12-bit A/D subsystem for IBM PC/XT/AT
		and compatible computers. It has its own pacing clock, data
		buffer and sequencing circuitry. Once programmed, it will
		run without host computer intervention until the data
		buffer is full. With the bundled software, the Model 102
		can stream continuous data to disk at rates up to 94 KHZ
		depending on the speed of your hard disk. Even a 10 MHZ XT
		class computer can stream to RAM disk at 45 KHZ. An AT
		class computer with a fast hard drive can stream to the
		hard disk at or near the maximum sampling rate of the card.
		Note that DMA is not used and interrupts are not required.
		This reduces the possibility of obscure incompatibilities
		causing reliability problems.

		    The 16K sample data buffer can be used in the
		conventional fashion or as a circular buffer, i.e. it can
		preserve pre-trigger as well as post-trigger data. A
		programmable counter determines the proportion of pre- and
		post-trigger scans. The data can be virtually all
		pre-trigger, virtually all post-trigger, or anywhere in
		between. The Model 102 also places information from two
		digital inputs with the analog data. These event marker
		inputs allow easy correlation of asynchronous activity. An
		external clock input and clock output are provided to
		further aid in synchronization.

		     Eight bits of optically isolated output and 4 bits of
		digital input (in addition to the two event markers) are
		provided. A 16-bit event counter is available for general
		purpose use in some modes of operation. Interrupt
		capabilities are also present. The support software
		supplied with the Model 102 serves as a no-frills data
		acquisition package. It also serves as an example for BASIC
		programmers. Because of the power and flexibility of the
		Model 102, some programming experience is recommended if
		you intend to incorporate the Model 102 drivers into your
		application software.

		     The bundled support program allows you to set up the
		Model 102 for your particular application through
		menu-driven software. In addition, you can save your set up
		on disk so that a given configuation can be easily
		recalled.

								        Page 3

		 SECTION 1.     Installation
		       Your Model 102 board comes packaged in pink
		anti-static material. The board should be returned to
		anti-static packaging whenever it is not installed in a
		computer.

		Note: Always handle printed circuit boards by the edges.

		      There are seven dip switches located near the bottom
		edge of the Model 102. These switches determine the base
		port address of the card. The base address can be placed
		virtually anywhere in the available I/O space, including
		places reserved by the operating system. We recommend
		addresses between 544 (220 Hexadecimal) and 624 (270 hex).
		The switch positions for base address 544 are 1,2,4,5 and 6
		ON; 3 and 7 OFF. If there are other special purpose cards
		in your computer you should check their documentation to
		make sure the port addresses do not conflict. There is also
		an interrupt level jumper near the gold edge connector. As
		shipped, the interrupts are disabled. If you want interrupt
		capabilities, you must dedicate interrupt level 3,5 or 7 to
		the Model 102. The Model 102 cannot share an interrupt
		level. For interrupt level 3, place the jumper horizontally
		on the highest pair of pins, for level 5, the middle pair,
		and for level 7, the lowest. To disable interrupts, place
		the jumper vertically on the upper right or leave it off.
		Make certain that you know the dip switch position of your
		card before closing the cover. Follow the directions in
		your Operations Manual for removing the cover of your
		computer. Remember to double check that the power is off.
		Install the Model 102 carefully in a vacant full length PC,
		XT, or AT expansion slot. Make sure the card is firmly
		seated in the connector. You will need to remove and later
		replace the screw at the metal mounting bracket. Reclose
		the case.

		FIGURE 1.      Base Address Dip Switch Selection Chart

						  1= ON          0= OFF
		Base address    Hex     7    6    5    4    3    2    1

		544             220     0    1    1    1    0    1    1
		552             228     0    1    1    1    0    1    0
		560             230     0    1    1    1    0    0    1
		568             238     0    1    1    1    0    0    0
		576             240     0    1    1    0    1    1    1
		584             248     0    1    1    0    1    1    0
		592             250     0    1    1    0    1    0    1
		600             258     0    1    1    0    1    0    0
		608             260     0    1    1    0    0    1    1
		616             268     0    1    1    0    0    1    0
		624             270     0    1    1    0    0    0    1

								        Page 4

		     The Model 102 requires 8 consecutive port addresses.
		Valid possibilities range from 256 to 998 decimal. To
		obtain the base address from the dip switch positions use 0
		for ON and 1 for OFF in the following formula. SW7 * 64 +
		SW6 * 32 + SW5 * 16 + SW4 * 8 + SW3 * 4 + SW2 * 2 + SW1.
		Multiply the above by 8 to obtain the base address.

		        Figure 2.      Connector Pinout

		Pin 13 . . Ground
						  Pin 25 . . -3 Analog input
		Pin 12 . . Digital output A
						  Pin 24 . . +3 Analog input
		Pin 11 . . Digital output B
						  Pin 23 . . -2 Analog input
		Pin 10 . . Digital output C
						  Pin 22 . . +2 Analog input
		Pin  9 . . Digital output D
						  Pin 21 . . -1 Analog input
		Pin  8 . . Guard
						  Pin 20 . . +1 Analog input
		Pin  7 . . Trigger input
						  Pin 19 . . -0 Analog input
		Pin  6 . . Ext. clock input
						  Pin 18 . . +0 Analog input
		Pin  5 . . Digital input 7
						  Pin 17 . . Digital output H
		Pin  4 . . Digital input 6
						  Pin 16 . . Digital output G
		Pin  3 . . Digital input 5
						  Pin 15 . . Digital output F
		Pin  2 . . Digital input 4
						  Pin 14 . . Digital output E
		Pin  1 . . Clock output

		     You will probably want to check the Model 102 for
		basic function with a DC voltage source. A 1.5 volt battery
		is convenient. Connect the positive battery terminal to the
		+0 input pin and the minus battery terminal to the -0 input
		pin. Because the inputs are fully differential, a third
		wire is required from the minus battery terminal to the
		chassis of the computer.

		Note: For maximum reliability connect all unused analog
		      inputs to ground.

		      Turn on the computer. If the Power On self-test
		(POST) does not behave normally, turn off the power
		immediately and refer to the Troubleshooting Section of
		this manual. Back up your support disk before continuing.

								       Page 5
		 SECTION 2.     Operation

		     Create a directory for the Model 102. Copy the
		programs on your support disk to that directory and make
		that directory the default directory. First type MSHERC to
		install the graphics drivers. Then type M102 to begin the
		program. You will be asked for the ADC (Analog to Digital
		Converter) address. If you have used the settings for port
		address 544, enter that number now. Otherwise enter the
		address corresponding to your dip switch setting. You
		should now see the main menu. The options are described
		below.

		 OPTION 1.   Read Digital Inputs

		     The current digital input information is shown.  The
		digital inputs will accept TTL or 5 volt CMOS logic levels
		or contact closures to ground. The screen reflects any
		changes immediately. Digital inputs 7 and 6 are the event
		marker inputs. Inputs 5 and 4 are general purpose digital
		inputs. The trigger and external clock inputs have special
		functions in some modes of operation, but they can always
		be read at this location. The scan-in-progress bit goes to
		a one while conversion is in progress. This bit would
		normally be needed only by assembly language programmers
		operating in single scan mode. The interrupt status bit
		switches from 0 to 1 when the data buffer is 1/4 full or
		3/4 full and from 1 to 0 when the buffer is 1/2 full or
		full.

		 OPTION 2.   Set digital outputs

		     All the digital outputs (except the clock output) are
		optically isolated. They do not put out any current,
		rather, they behave like switch closures to the guard pin.
		They are normally used in conjunction with external pull-up
		resistors. Digital outputs A,B,C and D are used to control
		the external multiplexers (if any). Digital outputs E,F,G,
		and H are available for any use. These are controlled by a
		4-bit word that is reset to zeros at power up.

		 OPTION 3.   The Mode Settings

		     Normally, it is assumed that the Model 102 will be run
		from its internal clock with the interrupts disabled.  You
		can change either of these using option 3. Most of the
		software functions will accept external clocking, but some
		care is required to avoid stray clocks when switching the
		clocking mode. The third mode bit, Circ Bf (Circular
		buffer), switches the auxiliary counter configuration.
		With Circ Bf off, the auxiliary counter is available for
		general purpose use. With Circ Bf on, the counter will
		count conversions and its output will switch the conversion
		clock on or off. Note that the circular buffer is left
		enabled after triggered acquisition.

								        Page 6
		 OPTION 4.   The Scanning Sequence

		     Two, three or four simultaneous channels may be
		digitized at each scan. Single channel data can also be
		taken. The scan sequence is defined by the first and last
		channel number for each scan. The channels are designated
		0,1,2, and 3 so a scan sequence of 0 to 3 would take four
		channels of data beginning with channel #0. Specifying
		channel 1 to 0 would also result in four channels/scan but
		the data would be stored with channel 1 first, then 2, 3
		and 0 last. For single-channel use the first and last
		channel numbers are the same. Remember that after changing
		the scanning sequence, the clock will be stopped. To
		distinguish the simultanaeous scans described above from
		the extended scans described below, the simultaneous scans
		will sometimes be called short scans.

		     Extended scanning is also possible.  Extended scans
		are groups of short scans done sequentially. External
		multiplexers are required for expansion beyond four
		channels. With four multiplexers, one on each input
		channel, sixteen groups of four simultaneous channels can
		be sampled sequentially.

		     A separate multiplexer is required for each
		simultaneous channel. The external scanning sequence is set
		in the same fashion as the short scanning sequence.
		Extended scan channels 0 to 15 are valid. Specifying
		external channels 4 to 9 would scan six channels,
		4,5,6,7,8,9,4,5,6,7,8,9...etc. If the short scan was for
		three channels, then three times six, or eighteen data
		points will be sampled and stored before the first repeats.
		If no external multiplexers are in use, specify 0 to 0. If
		only one external channel is to be used, enter that
		channel number as both the first and last channel, for
		example, 11 to 11. After changing the scanning sequence the
		read and write data buffer counters are realigned.

		 OPTION 5. Single Scan Operation

		     For single scan operation, conversions are performed
		when requested by the host computer. Selecting "Read Single
		Extended Scan" from the menu causes 1 to 16 short
		scans to be displayed. The external channel number is shown
		at the right edge of the screen. To the left is status
		information. The first character shown under "status" will
		switch from - to + and back periodically. This bit switches
		once for each 16K samples acquired. The next two characters
		are the event markers. They show "-" for a low level input
		and "6" or "7" respectively for a high level input. Note 
		that the event marker information is not current, instead, 
		it was latched at the time of the scan. Remember that
		selecting "Read Single Extended Scan" leaves the conversion
		clock off.

								       Page 7
		 OPTION 6.   Setting The Clock Rate

		     The scanning clock can be set in 1/2 microsecond
		intervals anywhere from 11 microseconds/scan (90.9KHZ) to
		30 milliseconds/scan (33HZ). Thereafter, periods up to ten
		minutes can be selected in 10 millisecond intervals. The
		scanning interval must be multiplied by the number of
		channels per scan to obtain the throughput. The software
		does not prevent you from selecting an unobtainable rate.
		Typical maximum scanning periods and rates are .0425
		milliseconds for four channels (23.5 KHZ scans or 94KHZ
		samples/second). For three channels a .0325 millisecond
		scanning interval yields a 30.8 KHZ scanning rate which
		corresponds to a 92.3 KHZ throughput. For two channels a
		.022 millisecond scanning interval yields a scanning rate
		of 45.5 KHZ and a throughput of 91 KHZ. The single channel
		sample interval must be .011 milliseconds(90.9 KHZ) or
		longer.

		     Note that when starting the software the clock rate is
		unknown, shown as ???. Not resetting the clock allows
		access to previously captured data which may be in the data
		buffer. Note that increasing the number of channels per
		short scan may raise the required throughput above
		attainable limits.

		 OPTION 7.    Viewing Buffer Contents

		     Data is stored sequentially in the 16K sample on-board
		data buffer. When the end of the buffer is reached, the
		data is again written at the buffer's beginning. Data is
		read by the host computer on a first in, first out basis.
		If data is to be read while sampling is proceeding, care
		must be taken to insure that data is not over-written
		before it can be read. Also, if data is read faster than it
		is being written, discontinuities will result. Data is
		displayed in the same format as in Option 5 above. If the
		conversion clock is running, the data may be overwritten as
		you watch. For clarity, you will probably want to turn off
		the conversion clock before selecting Option 7. If the
		number of samples per extended scan does not divide evenly
		into 16386, and the data is overwritten, then the channel
		labeling for subsequent buffers will not align. If you do
		not see meaningful data, read a single scan first, to
		realign the read and write counters, then reselect Option
		7. After that step you will begin reading from the start of
		the data buffer again.

		 OPTION 8.    Triggering/Streaming/Counting

		     Selecting this option brings up the Triggering menu.
		The possibilities are described below.

								       Page 8
		Do a preset number of scans

		     Once the scanning sequence and rate have been
		established, a block of data up to 16K samples in length
		can be captured. The start of the sampling period can be
		hardware or software controlled. If the external trigger
		input is at a high logic level, then sampling begins as
		soon as the N scans are programmed. If the external trigger
		is low (0 volts), sampling will not start until the trigger
		goes up. In addition, if the trigger goes down during the
		sampling period, the counting (but not the sampling) will
		stop until the trigger goes up again. The N scans are
		always written at the start of the sample buffer so a
		second N scans will overwrite the first.

		Pre/post triggering

		     You will be prompted for the number of pre-trigger
		extended scans. Once that information has been provided the
		card will be running, accumulating pre-trigger data. Make
		sure you wait long enough for the desired number of
		pre-trigger scans to complete before proceeding. Next
		you are asked if the trigger is a single event or a
		repetitive one. If you answer S for single, the card will
		immediately await a positive edge on the external trigger
		input. If you respond R for repetitive, first a negative
		edge is located and a few microseconds later, the card will
		look for a positive edge. This procedure reduces the chance
		of having the card trigger on a slightly ragged negative
		edge. Even so, a slowly changing trigger input may cause
		occasional negative edge triggering. A "waiting for
		trigger" message is displayed. After the trigger, you will
		see the auxiliary counter count down the programmed number
		of post-trigger scans to zero. Note that the post-trigger
		period will be restarted if a second trigger signal occurs
		before the post-trigger scans complete. In that case the
		counter may continue to count without ever reaching zero.
		If this happens, press a key and retry the process with a
		larger number of pre-trigger scans. Note that extended
		scanning is not supported in this mode.

		Read a counter/ Set a counter

		    These utilities have been included mainly as
		programmer's examples. The 8253 counter chip on the Model
		102 is the same one used in a standard XT computer.
		However, the counter has many modes and will behave
		strangely if mis-programmed. You can read the counters at
		will without fear of the consequences, but be wary of
		setting them. When not in circular buffer mode, the
		auxilliary counter (counter 2) can be set in mode 3 with a
		count of 0. Then the count read at counter 2 will reflect
		the number of negative edges at the external trigger input.
		Remember that the counters always count down and that they
		will roll over from a count of 0 to a count of 65535.

								     Page 9

		Stream to disk

		    First make sure the throughput required (in Option 6)
		is attainable with your disk drive. Then enter a
		valid file specification and provide the number of 8K
		data blocks to stream. Pressing a key during the
		streaming process will stop streaming without data loss.
		Streamed data files can't be longer than 2000M. Remember
		that you can stream to a RAM drive if one has been
		installed.

		Calculate maximum streaming rate

		     After you provide a valid file specification, the
		computer will first determine the variation in your disk
		access times. From that variation, it will calculate a
		target margin. Then it will begin speeding up the
		conversion clock until the margin is approached. When the
		disk stops, the minimum scanning interval will be
		displayed. Pressing any key during the process will cause
		it to stop without obtaining a maximum rate. Running this
		test repeatedly will not always produce the same
		result because of disk access variations. To be safe, you
		may want to run a few percent slower than the maximum
		displayed rate. If you want to push the limits, you may
		find that you can go slightly faster. A large number for
		BUFFERS in your CONFIG.SYS file may reduce the average disk
		access time while increasing access time variability.
		Because streaming is limited by the worst case access time,
		decreasing the BUFFERS setting in your CONFIG.SYS file to a
		minimum will probably maximize the streaming rate.

		Graphics

		    You will be asked if you want to graph a streamed file
		or the current contents of the data buffer. If the data
		buffer contains pre- and post-trigger data, it will be
		rearranged so that the first point in the buffer is the
		first point in time. Note that the justification process
		requires about 32k bytes of vacant disk space on the
		default drive. Next, you review the displayed compression
		factor, external scan number, the first channel to plot,
		and the number of channels to plot. A compression factor of
		1 plots normally, a factor of 2 overplots two points before
		advancing along the time axis thereby fitting double the
		data on the same screen. The first point to plot
		would normally be 0,1,2 or 3 if a short scan was four
		channels. The next entry, number of channels to plot, can
		be 1 to 4. If you chose to change any of the graphics
		parameters, you will be prompted for them and then given an
		opportunity to review the changes. Note that the channels
		are identified by their position in the scanning sequence
		and not by their control code or A/D channel number.

								      Page 10

		     You will see a Y axis with index marks every .5 volts.
		The X axis is at zero volts. Y axis resolution is one part
		in 320. Horizontally, 360 points are plotted. The trigger
		point is marked for circular buffer data. Beneath the graph
		are three lines. The top one is the overflow bit. Gaps here
		indicate discontinuous data. The next line is event marker
		6 with event marker 7 at the bottom. For the event markers,
		a thick line indicates a low logic level. In the lower left
		corner of the screen is the first and last extended scan
		number currently being displayed. In the lower right is the
		elapsed time for the entire screen. Between are listed the
		valid commands. Commands are invoked by entering the first
		letter. N for New allows different channels from the same
		file to be graphed or a change of the compression factor. M
		returns to the Menu. The other commands, Page, Frame, and
		Dot each provide movement forward or backward through the
		data. If the shift key is not depressed, (Caps lock off), p
		will page forward through the data, f will advance 30 scans
		and d will advance one scan. Direction is reversed if
		shifted. A beep will sound if an end of the data buffer is
		reached. Note that only 16K samples are in the data buffer
		at any one time, so large compression factors or large
		extended scans can lead to fewer than 360 plotted points
		available in the data buffer. In that case, the plot will
		be shorter than 360 points. Also, under those conditions,
		the framing is disabled and the paging will not be as
		fluid.

		Files

		     Option F on the main menu will yield the Filing menu.
		Four options are described below. The fifth option is
		"Return to main menu".

		1) Save current graphics buffer
		    This option will write a 16K sample (32K byte) binary
		file with the specified file name and path. You may want to
		add a .bin file name extension to distinguish the file from
		its ASCII counterpart. The files produced have the same
		size and format as a streaming file with two 8K sample
		blocks specified. These files can be loaded for examination
		by the Graphics section or used as input files for the
		ASCII conversion option described below.

		2) Load graphics buffer from disk
		    This option will read a 16K sample (32K byte) binary
		file with the specified file name and path. If a longer
		streaming file is specified, the first 16K samples only
		will be loaded.

								      Page 11

		3) Convert binary file to ASCII file
		     Binary files are bit image files as read from the
		Model 102 A/D card. They are used internally by this
		program for graphics and data manipulation. When you want
		to transfer data to another program you will need to
		convert your data to ASCII format. ASCII files can also be
		viewed using the DOS "TYPE" command. You first must provide
		the name of the desired binary input file. That file can be
		either a streaming file or a 16K sample file written using
		option 1 above. Next, you provide an output file name. If
		your file is to be imported into Lotus, you must use a .prn
		file extension. Remember that any pre-existing file with
		the same name will be destroyed. Next, you can choose to
		have the event marker data included in your file. Finally,
		you select for Lotus or interlaced DADiSP style file
		format. The ASCII format file will be 4 to 5 times the size
		of the input file, so be sure plenty of disk space is
		available. Because the file conversion is coded in assembly
		language using a look-up table, the conversion speed is
		limited almost entirely by the speed of your disk drive.
		An AT class computer with an average hard drive can
		convert an 800K input file to ASCII in a minute. After
		the file conversion is complete, if there are any
		discontinuities in your data, the number will be displayed.
		Discontinuities are usually due to streaming data at higher
		that sustainable rates. If your input file was not a
		streamed data file, one discontinuity is expected. If your
		input file was a "do N scans file" with undefined data in
		some of the data buffer, you should ignore the discontinuous
		data warning.

		    Because the input for the data conversion always comes
		from the disk, you must save the data before converting it.
		Select grphics (option 9) to preview the data, then, select
		F for Filing and using option 1 above, save the graphics
		buffer contents. If the data was taken in circular buffer
		mode, the data will be justified when you preview the data.
		Don't switch out of circular buffer mode before you have
		viewed your data or it will be overwritten. The file
		formats are shown below.

		LOTUS (with markers):

		"DATASET file specification"
		"DATE 05-20-1990"
		"TIME 11:39:40.00"
		"INTERVAL .05 "
		"AD0-Ex0","Event","AD1-Ex0","Event","AD2-Ex0","Event",
		"AD3-Ex0","Event"
		+1002 2 +0002 2 -3543 6 +1822 6
		+1004 7 +0101 7 -3521 7 +1822 0
		etc.

								      Page 12

		     The Lotus file format has all text in quotation marks.
		To import the data, use worksheet/file/import/numbers. Long
		scans will occupy rows and data points occupy columns. The
		Lotus file header contains the filename, the time and date
		that the file was converted (not written), and the scanning
		interval in milliseconds. The channels are labeled using
		the A/D channel number and external control code. All
		voltages are scaled in millivolts. The marker digit will be
		6 if digital input 6 only is high, 7 if input 7 only is
		high, or 2 if both input 6 and 7 are up. If neither input
		is high, the markers digit will be 0.

		    The DADiSP header is basically the same but labels are
		not quoted and some additional housekeeping information is
		required. If marker information is included, it will be in
		the same format as for Lotus files, above.

		DADiSP (without markers):

		DATASET file specification
		VERSION :NXT
		NUM_SIGS 4
		DATE 05-20-1990
		TIME 11:39:40.00
		INTERVAL .05
		STORAGE_MODE INTERLACED
		CHAN_NAME AD0-Ex0,AD1-Ex0,AD2-Ex0,AD3-Ex0
		VERTICAL UNITS mv,mv,mv,mv
		HORZ_UNITS Seconds
		DATA
		+1002 +0002 -3543 +1822
		+1004 +0101 -3521 +1822
		etc.

		4) DOS Shell
		    This option gives you access to DOS without exiting the
		program. You can check file contents with the TYPE command,
		backup your data files, or check directory contents. You
		probably do not want to run another program under the DOS
		shell.  There must be a copy of command.com in the search
		path for the shell to work properly. Type exit to return to
		the file menu.

		    When you selext X to Exit from the main menu, you are
		asked if you want to save the configuration. If you respond
		Y, then the current settings will overwrite the previous
		ones in the M102.CFG file in the default directory.

								      Page 13

		 SECTION 3.     Programming

		     The source code for the Model 102 is included on your
		program disk. The high level language is QuickBASIC 4.5.
		The code is heavily remarked. We recommend changing the
		subroutines themselves as little as possible because the
		exact order of many of the hardware-related instructions is
		significant. Programmers must start QuickBasic with the
		libraries option:

		           QB M102/L GRAPH

		     All the time-critical drivers for the Model 102 are in
		a GRAPH library. The library is written for the Microsoft
		Assembler version 5.1. The source file for GRAPH is 
		GRAPH.ASM. If you want to modify the GRAPH library, you 
		should follow this sequence to obtain a new executable file:

		           MASM GRAPH;
		           LINK GRAPH BQLB45.LIB;
		           ERASE GRAPH.LIB
		           LIB GRAPH.LIB+GRAPH.OBJ;
		           BC M102/O/X;
		           LINK M102+GRAPH.LIB;

		     The resulting files are, in order, GRAPH.OBJ,
		GRAPH.QBL, GRAPH.LIB, M102.OBJ and M102.EXE. The first LINK
		may produce two unresolved external reference errors. To
		the best of our knowledge, they are harmless. If you change
		the M102.BAS file, only the last two steps are needed.
		     The hardware registers are fully described early in
		the M102.BAS source code. The sections concerning the
		fundamental operation of the card are straightforward and
		should be reasonably easy to follow. The graphics section
		is more complex and less linear. It is intended less as a
		programmer's model than as a quick way to get a look at
		the data. EGA drivers and other enhancements are planned
		for the not too distant future.

		     The interrupt protocol for PC/XT/AT computers is
		under-defined and conflict prone. Therefore Lawson Labs
		policy is to avoid interrupts to maximize reliability. We
		acknowlege, however, that there are legitimate uses for
		interrupts and have provided some hardware interrupt
		capability on the Model 102. In Circ Bf mode interrupts
		(if enabled) are generated by a negative edge at the output
		of the auxiliary counter. When out of Circ Bf mode
		(streaming or polled operation), interrupts (if enabled)
		occur when the data buffer is 1/2 full or full.

		     Every effort has been made to insure hardware and
		software compatibility. If you should uncover any problems,
		please report them to Lawson Labs. We will address them
		promptly and courteously.

								      Page 14

		 SECTION 4.     Troubleshooting

		A.   Power On Self Test (POST) does not work with card
		        installed or card shows no function at all

		     First, check that the card is properly seated in the
		expansion connector. Then, check the dip switch positions 
		and interrupt jumper position. There may be some other 
		device using the port address you have selected. Try an 
		ADC of 768 (300 hex). Starting with switch 7, and using 1 
		for ON, that becomes 1100000.

		B.   Card shows poor reproducibility

		     Remember that the inputs are differential and that
		both the plus and minus inputs must be within 6 volts of
		ground.  Try adding a wire connecting the minus voltage
		source and chassis ground at the computer. A steady voltage
		should yield a steady reading +/- 1 count.

		C.   Card won't capture data

		     Check the mode setting. In circular buffer mode the
		conversion clock can be shut off by the auxiliary counter.
		If you have inadvertantly set the card for an external
		clock, and none is present, no conversions will be done.
		You can tell if the clock itself is running by selecting
		"Read a counter" from the triggering menu and reading
		counter 1. If the counter is going, return to the main menu
		and select "Read digital inputs". The interrupt status bit
		should change once every 4K samples have been acquired. If
		it does not, the external clock must be enabled but not
		running. Also, double-check the throughput as shown at
		Option 6. If you attempt a throughput higher than possible,
		your data will be corrupted.

		D.  Channels are not labeled properly

		     The various channels are identified only by their
		relative positions in the data buffer. Any stray data reads
		will upset the process. If the scanning sequence, as
		currently specified, does not match the capture sequence,
		then the data will be mixed. Restarting the clock also
		resets the read and write counters. If that fails to
		realign the data, then use single scan mode to sort out the
		problem. Also, in triggered operation, the card cannot
		necessarily find its place in the external scanning
		sequence. If you need to use extended scanning in circular
		buffer mode, you must dedicate one channel to a distinctive
		signal and manually align the external scanning sequence.

								      Page 15

		E.  Data in circular buffer is discontinuous

		     The Model 102 must have been running for at least the
		time required to take the necessary number of pre-trigger
		scans before a trigger occurs or else some of the
		pre-trigger data will be spurious. Make sure to wait the
		required time before selecting single or repetitive
		trigger.

		F.  Data "capture N samples" buffer is discontinuous

		     In this mode, the N sample counter will stop whenever
		the external trigger output is low. You will probably find
		that a low trigger input caused extra samples to be taken
		causing the buffer to overfill. Remember that the data
		buffer will still contain old data beyond the specified
		number of scans.

		G.  Data in streaming files is discontinuous

		     You are probably going to have to slow down the
		conversion clock. Try reducing the number of BUFFERS in
		your CONFIG.SYS file. It may also be that a statistically
		unlikely series of unsuccessful write attempts caused the
		disk to fall behind. A disk performance utility may
		reorganize your drive for greater efficiency. It can also
		tell you if your disk is suffering from an excessive number
		of read/write errors.

		H.  The external multiplexers are not switching properly

		     First make sure the multiplexer ground is connected to
		the guard terminal on the Model 102. Also remember that the
		multiplexer has a significant switching time. If the
		multiplexers work in single scan mode but not at speed, the
		problem is probably switching time. The A,B,C & D
		lines are clocked at the beginning of each sort scan.
		Depending on the number of multiplexers connected, the
		maximum scanning rate may be as slow as 10K. Contact Lawson
		Labs for ways to speed up the external multiplexers.

		I.   Cross talk between channels

		     Usually, cross talk can be traced to the cabling.
		Higher source impedances are more susceptible to crosstalk.
		Use twisted pairs of wire for each input channel or, in
		extreme cases, separate shieiding may be required. If any
		of your signals have very high rates of change, there may
		be a slight (1 or 2 counts) influence on another channel.
		Because the Model 102 cannot capture very high frequencies
		anyway, the recommended solution is to pre-filter the fast
		signal to slow the rise and fall times.

								      Page 16

		J.  Digital outputs not working

		     The digital outputs are optically isolated from the
		computer. They function relative to the guard pin on the
		Model 102 only. Normally they require a pull-up resistor to
		an external power supply. The ground on the external supply
		should be connected to guard. The maximum recommended power
		supply voltage is 24 VDC. The maximum recommended operating
		current is 5 milliamps. That dictates a pull-up resistor of
		1000 Ohms or larger for a 5 VDC supply. The smaller the
		pull-up resistor, the faster the outputs will operate.

		K.  Single buffer data is overwritten

		    The Circ Bf mode bit must remain set until the data is
		read from the A/D card buffer. If the clock is running and
		sampling was stopped by the auxiliary counter, then
		clearing the Circ Bf bit will overwrite your data.

		L.  Circular buffer not justified

		    The graphics section will attempt to justify data if
		the Circ Bf bit is active and the auxilliary counter
		(counter 2) is in mode 5. These conditions would normally
		prevail. If you change the mode or reprogram counter 2
		before previewing your data, then
		jusification will not be done.

		M.  Minus Overrange voltage read positive

		    If an input voltage goes much below the -6 volt common
		mode limit, that channel will read +5VDC. This is normal.

		 SECTION 5.     Internal Adjustments

		     The internal adjustments are factory set and your
		Model 102 should not need periodic recalibration. There are
		6 trimpots along the top edge of the Model 102. The round
		trimpot nearest the input connector is a non-critical trim
		for setting the -8 VDC power supply. It should not need
		adjustment. The next trimpot towards the keyboard is the
		gain adjustment. It allows the full scale sensitivity to be
		varied between +/-5 VDC and +/-3 VDC. The single gain
		adjustment affects all 4 channels. The last four trimpots
		are offset adjustments for input channels 0 through 3. The
		trimpot nearest the keyboard is channel 0. These can be
		adjusted to read zero volts when both the + and - input
		pins for that channel are at ground potential.

								     Page 17

		SECTION 6    Model 102 Specifications
		             for PC/XT/AT type computers

		Capture 1,2,3 or 4 simultaneous channels

		+/- 5 VDC full scale input range

		+/- 6 VDC input common mode range

		Overvoltage up to +/- 15 VDC without cross-channel 
		      interaction up to +/- 75 VDC continuous without 
		      damage transients up to 120 VDC without damage

		12-bit resolution with no missing codes

		+/-1 count reproducibility

		Sampling interval programmable from 11 microseconds 
			(90.9KHZ) to 300 milliseconds (33HZ) in 
			.5 microsecond intervals and programmable from 
			300 milliseconds to 10 minutes with 10 millisecond 
			resolution internal or external clocking

		Overall DC accuracy +/- 0.1%

		Interchannel skew +/- 5 nanoseconds maximum

		Full power bandwidth 22.5KHZ  (-3db)

		16K sample on-board data buffer

		Flexible pre/post triggering capability

		2 4-bit optically isolated output ports with 5 milliamp
		        current sink capability, external pull-up required

		6 bits digital input including 2 event markers, inputs are
		        compatible with TTL, 5V CMOS, and contact closures

		Externally expandable to 16 sets of 4 simultaneous channels
		General purpose 16-bit event counter

		Typical power consumption         5 VDC     350 MA
				              +/- 12 VDC      60 MA each

		Size           full length XT style card
				3.9 x 13.9 x .75 inches

								      Page 18

				        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. Contact Lawson Labs,
		Inc. at 610 725-8800 or 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.