Lawson Labs, Inc.
15 Phoenixville Pike 
Malvern, PA   19355
610 725-8800
800 321-5355
lawsnlab@netaxs.com


		  Model 135 DLL with sample EasyWin  
		      the EasyWin is written in
		Borland C++ 4.5 for Windows 3.x or 95
		-------------------------------------

These instructions assume a Borland C++ compiler.  The following files 
are included on the disk and most are needed to compile and run the example
program:

135DLL   DLL  
135EWIN  CFG  
135EWIN  CPP  
DEFAULT  DEF  
135EWIN  OBJ  
135      H    
135EWIN  IDE  
135EWIN  EXE  

The above files should all be located in the same directory.  


135EWIN shows two modes of operation: polled and scanning. The polled mode
example is similar to DEMO135.BAS. The scanning example roughly parallels
DRIVR135.BAS.  

The principle differences in scanning function between DRIVR135 (DOS) and
135EWIN (Windows) are described below. 

1) Timing in DOS is achieved by running the converter continuously and
counting conversions. In Windows, the real time clock (counter 0) is  
used as the time base. Timing accuracy on the average should fall within 
a few microseconds. Occasional 100 microsecond timing irregularities will   
occur. Setting interrupts to OFF improves timing somewhat, but does not 
prevent Windows from periodically borrowing a block of time.
   The timing precision obtainable in any particular case will depend on 
the percentage of resources given to the Model 134 code and the number 
and nature of other concurrent tasks. Disk access, for example, will 
normally take priority over data acquisition.

2) The maximum throughput in Windows is slightly slower. Also, a faster
computer is needed to achieve maximum speed. 

3) The Windows version can assign a much larger block of memory as a data
buffer.

4) The structure passed to the driver has been simplified without sacrificing 
function. This streamlining is accomplished by moving set-up and housekeeping
calculations into the DLL.



Troubleshooting
---------------
Program will compile and link, but won't run, or gives an error when trying
to run:
  Make sure that the 135DLL.DLL file is in the current directory or in the
  WINDOWS directory.

Program will will run but cannot get past the main menu screen:
  Make sure that the Model 135 is seated correctly in the card slot, and
  the ADC address is correct. Verify Model 135 function using DEMO135 if 
  you don't get proper response.

Channels interact on external multiplexer:
  Lengthen interchannel delay. The standard 17B mux can require as much
  as a mllisecond interchannel delay time.

Signals are noisy: 
  See your Model 135 manual for grounding and shielding instructions. 
