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GoFiler Legato Script Reference

 

Legato v 1.5b

Application v 5.24b

  

 

Chapter TwelveInternet Functions (continued)

SerialRxCharacter Function

Overview

The SerialRxCharacter function pulls a single character (byte) from the receive queue.

Syntax/Parameters

Syntax

int = SerialRxCharacter ( handle hSerial, [int ms] );

Parameters

hSerial

A handle to a Serial Port Object.

ms

An optional int specifying how long to wait in milliseconds for a character. If no characters become available during the wait period, an ERROR_EOD will be returned. The default value is -1 indicating to wait the default amount of time.

Return Value

Returns an int as a character or a formatted error code on failure. Use the GetLastError to retrieve a formatted error code. On timeout ERROR_EOD is returned.

Remarks

SerialRxCharacter reads a single character from the queue. If a timeout value is specified, the function will wait the specified time for a character. Should a character not arrive in time, an error is returned. The function checks the receive queue and if no data is available checks the timeout and releases (sleeps) the thread and tries again.

Reading single characters from a serial channel is a low-level operation and is not efficient. Further, the receive queue differs from the receive buffer. If a receive operation times out and characters remain in the receive buffer, this function will not retrieve those characters. Caution should be exercised when mixing single character operations with buffer and line operations.

Related Functions

Platform Support

Go13, Go16, GoFiler Complete, GoFiler Corporate, GoFiler, GoFiler Lite, GoXBRL

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