LumaSense Technologies M390S User Manual

Page 31

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M390 Manual

Appendix B: ASCII/BASIC 31

A simple BASIC program to send blackbody setpoint:

CLS

'-----open comm port 1 for 9600 baud, 7,E,1-----
OPEN "COM1:9600,E,7,1,RS,CS,DS" FOR RANDOM AS #1

inman:

'-----enter desired setpoint as a string---

INPUT "Enter setpoint temperature (EXIT to quit) "; sp$

'-----always make it upper case for text entry---
IF UCASE$(sp$) = "EXIT" THEN GOTO endman

'-----make the setpoint a number----

sp = VAL(sp$)

'-----retry if the entry was out of range of the blackbody--

‘IF sp < 600 OR sp > 3000 THEN PRINT "invalid entry": GOTO inman

'format setpoint to match controller

'---display the setpoint--

PRINT sp

'-----make a string that is 100 times the sp value---

sp = sp * 100
spi = FIX(sp)

spi$ = STR$(spi)

'-----extract the two decimal values (.nn) from the string--

decpt$ = RIGHT$(spi$, 2)

'-----extract the integer values from the string--
integer$ = MID$(spi$, 2, LEN(spi$) - 3)

'-----generate the variable setpoint set string (SLnn.nn(ascii

'heart symbol'))

setpoint$ = "SL" + integer$ + "." + decpt$ + CHR$(3) 'generate

partial sp string
'-----chr$(n) is the hex value of n taken from the table section

4.1.5 in Eurotherm

'-----comm instruction manual

'generate checksum (if needed)

x = 0
FOR c = 1 TO LEN(setpoint$)

x = x XOR ASC(MID$(setpoint$, c, 1))

NEXT c

' The "0011" in the string below is address 01. To talk to

address 02, use 0022
' (Each address digit is reapeated for confirmation)

' To send to address 03, use "0033".

' To send to address 04, use "0044".

' To send to address 15, use "1155", etc.

'-----generate the full setpoint string--
setpoints$ = CHR$(4) + "0011" + CHR$(2) + setpoint$ + CHR$(x)

'full setpoint string

'-----chr$(4) is diamond symbol

'-----chr$(2) is 'happy face' symbol

'---display the setpoint string---

PRINT "string sent="; setpoints$

'----send the string to controller---

start:

PRINT #1, setpoints$ 'send to controller

'---repeat as required--
GOTO inman

endman: CLOSE 1

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