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(Created page with "The LOC function returns the status of a serial (COM) port received buffer or the current byte position in an open file. {{PageSyntax}} : {{Parameter|bytes%}} = LOC({{Parameter|fileOrPortNumber%}}) * {{Parameter|fileOrPortNumber%}} is the number used in the port OPEN AS statement. * Returns 0 if the buffer is empty. Any value above 0 indicates the COM port has received data. * Use it in conjunction with INPUT$ to get the data bytes received. * Can also be...") Tag: visualeditor-switched |
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{{PageExamples}} | {{PageExamples}} | ||
''Example:'' Reading and writing from a COM port opened in Basic. | ''Example:'' Reading and writing from a COM port opened in Basic. | ||
{{CodeStart}} | {{CodeStart}} | ||
{{Cl|OPEN}} "{{Cl|OPEN_COM|COM}}1: 9600,N,8,1,OP0" {{Cl|FOR (file statement)|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #1 {{Cl|LEN}} = 2048 ' random mode = input and output | {{Cl|OPEN}} "{{Cl|OPEN_COM|COM}}1: 9600,N,8,1,OP0" {{Cl|FOR (file statement)|FOR}} {{Cl|RANDOM}} {{Cl|AS}} #1 {{Cl|LEN}} = 2048 ' random mode = input and output | ||
{{Cl|DO}}: t$ = {{Cl|INKEY$}} ' get any transmit keypresses from user | {{Cl|DO}}: t$ = {{Cl|INKEY$}} ' get any transmit keypresses from user | ||
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r$ = {{Cl|INPUT$}}(bytes%, 1) ' get bytes in the receive buffer | r$ = {{Cl|INPUT$}}(bytes%, 1) ' get bytes in the receive buffer | ||
{{Cl|PRINT}} r$; ' print byte strings consecutively to screen" | {{Cl|PRINT}} r$; ' print byte strings consecutively to screen" | ||
{{Cl|END IF}} | {{Cl|END IF}} | ||
{{Cl|LOOP}} {{Cl|UNTIL}} t$ = {{Cl|CHR$}}(27) 'escape key exit | {{Cl|LOOP}} {{Cl|UNTIL}} t$ = {{Cl|CHR$}}(27) 'escape key exit | ||
{{Cl|CLOSE}} # | {{Cl|CLOSE}} # | ||
{{CodeEnd}} | {{CodeEnd}} | ||
Revision as of 01:58, 23 January 2023
The LOC function returns the status of a serial (COM) port received buffer or the current byte position in an open file.
Syntax
- bytes% = LOC(fileOrPortNumber%)
- fileOrPortNumber% is the number used in the port OPEN AS statement.
- Returns 0 if the buffer is empty. Any value above 0 indicates the COM port has received data.
- Use it in conjunction with INPUT$ to get the data bytes received.
- Can also be used to read the current position in a file routine. See SEEK.
Examples
Example: Reading and writing from a COM port opened in Basic.
OPEN "COM1: 9600,N,8,1,OP0" FOR RANDOM AS #1 LEN = 2048 ' random mode = input and output DO: t$ = INKEY$ ' get any transmit keypresses from user IF LEN(t$) THEN PRINT #1, t$ ' send keyboard byte to transmit buffer bytes% = LOC(1) ' bytes in buffer IF bytes% THEN ' check receive buffer for data" r$ = INPUT$(bytes%, 1) ' get bytes in the receive buffer PRINT r$; ' print byte strings consecutively to screen" END IF LOOP UNTIL t$ = CHR$(27) 'escape key exit CLOSE # |