Thank you for the answer but it isn't.

Thats my code:

use Fcntl qw/:DEFAULT/;
use IO::Termios ();
use IO::Stty ();

sysopen my $fh, '/dev/ttyUSB0', O_RDWR or die "sysopen: $!";
my $handle = IO::Termios->new($fh) or die "IO::Termios->new: $!";
$handle->set_mode('300,7,e,1');
IO::Stty::stty($handle, qw/ raw -parodd cs7 -cstopb parenb -ixoff -crt
+scts -hupcl -ixon -opost -onlcr -isig -icanon -iexten -echo -echoe -e
+choctl -echoke/);

my $raw = "\x2F\x3F\x21\x0D\x0A";
$handle->syswrite($raw) == length($raw) or die "syswrite";
my $raw = "\x06\x30\x30\x30\x0D\x0A";
$handle->syswrite($raw) == length($raw) or die "syswrite";

for (1..300) {
    my $toread = 1;
    $handle->sysread(my $in, $toread)
        == $toread or die "sysread";
    print $in;
}

$handle->close;
[download]

And it is always the same output:

/?!
000
/LOG4LK13BD202015
[download]

Thats all - thats not, what I need

2019-05-28 Athanasius added code tags

---

In reply to Re^2: r/w attached infrared head on /dev/ttyUSB0 by stoerti
in thread r/w attached infrared head on /dev/ttyUSB0 by stoerti

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.