'Lawson Labs, Inc.
 '3217 Phoenixville Pike
 'Malvern, PA 19355
 '610 725-8800 or 800 321-5355
 'www.lawsonlabs.com
 '
 '
 'Sample driver for controling a DO16 relay board from an LPT1 or LPT2 port
 '
 'Common parallel port addresses are &H278, &H378, or &H3BC
 ' If you don't know your LPT base address, it is normally displayed
 ' during the beginning of the boot process. For Windows, you may
 ' need to press Esc to see the text screen. Press Pause if the
 ' information does not stay long enough on the screen.

 CLS : KEY OFF
 LPTADDR = &H3BC:      'put your LPT base address here
 LOCATE 24, 20: PRINT "Press Enter to exit";
 LOCATE 1, 1
 '
ReEnter:                'get the number of the relay to change
 INPUT "Enter relay number (1-16) "; Rly$
 IF Rly$ = "" THEN PRINT " Done": END
 Rly% = VAL(Rly$)
 IF Rly% > 16 OR Rly% < 1 THEN GOTO ReEnter

ReEnter1:               'get the new state for the relay
 INPUT "Enter 1 for ON or 0 for OFF"; State$
 IF State$ = "" THEN PRINT " Done": END
 State% = VAL(State$)
 IF State% > 1 OR State% < 0 THEN GOTO ReEnter1

 PRINT "setting relay"; Rly%; " to ";
 IF State% = 1 THEN PRINT "ON" ELSE PRINT "OFF"
 CODE% = State% * 32 + (Rly% - 1) XOR 207
 OUT LPTADDR, CODE%
 OUT LPTADDR, CODE% - 64
 OUT LPTADDR, CODE%
 PRINT
GOTO ReEnter


 '
 'DO16 relay contacts: Max voltage= 140 volts
 '                      Max current= 0.5 amps
 '                      Max power=   8 watts (volts * amps)
 '
 ' Interconnections:
 ' LPT1 or LPT2 connector pin#       DO16 terminal 
 '              2 ------------------ A   (address)
 '              3 ------------------ B   (address)
 '              4 ------------------ C   (address)
 '              5 ------------------ D   (address)
 '              7 ------------------ F   (on or off)
 '              8 ------------------ G   (strobe)
 '             25  ------------*-----GND (ground)
 '                             |     +5  (+5 VDC)
 '                             |     |
 '                             |     |
 '                             |     |
 '  5 Volt DC Power Supply:  GND    +5
 '
 'Power supply must provide at least 60 MA per active relay

'NOTE: Fast languages on fast computers may require a short
'      pause after each OUT instruction. 10 microseconds should
'      be long enough.