The LINESTATUS function returns information on the status of the RTS and DTR signals for a specified line.
Format
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LINESTATUS(line-expr) |
Parameter(s)
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line-expr |
An expression evaluating to the line number to check. |
Description
The LINESTATUS function returns two characters, representing whether the RTS or DTR signals are high for the specified line. The RTS signal is the Request-To-Send signal, which is high when the attached device is ready to send data. The DTR signal is the Data-Terminal-Ready signal, which is high when the attached device is ready to receive data.
The LINESTATUS function returns a two-digit string, of the form:
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rd |
Parameter(s)
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r |
0 if RTS is low, 1 if RTS is high. |
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d |
0 if DTR is low, 1 if DTR is high. |
Example
In this application a modem is linked to the line MODEMLINE. Before attempting to dial a modem, a program checks that DTR is high.
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LS = LINESTATUS(MODEMLINE) DTR = LS [ 2 , 1 ] IF DTR = "1" THEN GOSUB DIAL END ELSE PRINT "DTR IS LOW. CHECK MODEM CONNECTIONS" GOSUB EXIT END |
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NOTE |
The LINESTATUS function does not return information on the status of the RTS and DTR signals for the line linked to the console port. |
See Also