4D v18
SET TIMEOUT
SET TIMEOUT
| SET TIMEOUT ( seconds ) | ||||||||
| Parameter | Type | Description | ||||||
| seconds | Longint |
|
Seconds until the timeout | |||||
SET TIMEOUT specifies how much time a serial port command has to complete. If the serial port command does not complete within the specified time, seconds, the serial port command is canceled, an error -9990 is generated, and the OK system variable is set to 0. You can catch the error with an error-handling method installed using ON ERR CALL.
Note that the time is the total time allowed for the command to execute, not the time between characters received. To cancel a previous setting and stop monitoring serial port communication, use a setting of 0 for seconds.
The commands that are affected by the timeout setting are:
The following example sets the serial port to receive data. It then sets a time-out. The data is read with RECEIVE PACKET. If the data is not received in time, an error occurs:
SET CHANNEL(MacOS serial port;Speed 9600+Data bits 8+Stop bits one+Parity none) ` Open Serial Port
SET TIMEOUT(10) ` Set the timeout for 10 seconds
ON ERR CALL("CATCH COM ERRORS") ` Do not let the method being interrupted
RECEIVE PACKET(vtBuffer;Char(13)) ` Read until a carriage return is met
If(OK=0)
ALERT("Error receiving data.")
Else
[People]Name:=vtBuffer ` Save received data in a field
End if
ON ERR CALL("")
ON ERR CALL
RECEIVE BUFFER
RECEIVE PACKET
RECEIVE RECORD
RECEIVE VARIABLE
Product: 4D
Theme: Communications
Number:
268
Created: < 4D v6
4D Language Reference ( 4D v18)
