Hi All,

I need to manipulate data sent from a Nurse call system ( Device::SerialPort ). The Nurse call system introduces delays during transmission, it gets interpreted by my code as a newline.

lookfor() by default looks for \n and works fine in testing when there is no delay. 

#/usr/bin/perl
use Device::SerialPort;
my $port = Device::SerialPort->new("/dev/ttyUSB0");

$port->baudrate(9600); # Configure this to match your device
$port->databits(8);
$port->parity("none");
$port->stopbits(1);
$port->stty_icrnl(1);
$port->handshake("none") || print "failed setting handshake";
$port->write_settings    || print "no settings";
$port->buffers(4096, 4096);       
@max_values = $port->buffer_max;   
$port->reset_error;

while (1) {

my $char = $port->lookfor();
 if ($char) {
        print "$char\n";
open (DO, '>/home/pi/temp.txt');
print DO $char;
close DO;

    }
    $port->lookclear; # needed to prevent blocking
    sleep (1);
}

[download]

If I use this code to send data to the script, it works fine: 

$port->write("26Jul1998 16:00   P000 0080 CALL  , unit 0\r\n");

[download]

To reproduce the Nurse call system transmission, I use this: 

#/usr/bin/perl

use Device::SerialPort;
my $port = Device::SerialPort->new("/dev/ttyUSB0");

$port->baudrate(9600); # Configure this to match your device
$port->databits(8);
$port->parity("none");
$port->stopbits(1);
$port->handshake("none") || die "failed setting handshake";
$port->write_settings    || die "no settings";

$port->write("26Jul1998 16:00");
sleep(1);
$port->write("   P000 0070 CALL ");
$sleep(1);
$port->write(" , unit 0\r\n");

[download]

I have done a Hex dump of the Nurse call system transmission and confirmed there is no hidden new lines or cartridge returns. I'd appreciate any tips. Thanks you.

In reply to Serial data delay by StepSteve

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