Appendix d: programming 20, Appendix d: programming – Sensoray 421 User Manual

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Sensoray Model 421 Instruction Manual

Appendix D: Programming

Sample QuickBasic code segments are listed below to illustrate programming interface techniques for the 421
board. If you are coding your application in a language other than QuickBasic, you may find these listings
useful as a framework for writing your own drivers.

Although these listings are intended principally as programming examples, they may be used as is (or with
minor modification) as a basic set of interface drivers for the 421.

Feel free to modify, plagiarize and adapt these listings to suit your application requirements.

‘****************************************************************************
‘ SAMPLE QUICKBASIC INTERFACE CODE FOR THE 421
‘****************************************************************************

CONST BASEPORT = &H3A0

‘421 I/O base address

‘ Write-only I/O ports:
CONST DAC0LSB = BASEPORT + 0

‘DAC data registers

CONST RESETPORT = BASEPORT + 11

‘board reset

CONST CHCTRL = BASEPORT + 12

‘ADC channel reg / watchdog, DAC enables

CONST ADSTART = BASEPORT + 13

‘start A/D

CONST CNTCTL = BASEPORT + 14

‘encoder control port

CONST HITDOG = BASEPORT + 15

‘watchdog refresh

‘ Read-only I/O ports:
CONST LDAC = BASEPORT + 0

‘DAC update port

CONST STATUSPORT = BASEPORT + 11

‘board status

CONST ADLSB = BASEPORT + 12

‘A/D least-significant byte

CONST ADMSB = BASEPORT + 13

‘A/D most-significant nibble

CONST CNTLSB = BASEPORT + 14

‘encoder least-significant byte

CONST CNTMSB = BASEPORT + 15

‘encoder most-significant byte

‘ Read/Write I/O ports:
CONST RELAY0 = BASEPORT + 8

‘relay channel low bank access ports

CONST RELAY2 = BASEPORT + 16

‘relay channel high bank access ports

‘ CHCTRL port bit constants:
CONST DOGBIT = 1

‘watchdog enable/disable control bit

CONST DACBIT = 2

‘DAC output enable/disable control bit

‘ Boolean constants:
CONST FALSE = 0
CONST TRUE = NOT FALSE

‘ Variables that are visible throughout this module:
DIM SHARED relay%(0 To 5)

‘image of relay channel output registers

DIM SHARED chctrlImage%

‘image of CHCTRL output port

Module Level Code