EMC Professional NET
20
21
EMC Professional NET
4.2 Operation under Linux (NTP)
EMC Prof NET (19“)
can be used with
NTP
under Linux. „NTP“
means Network Time Protocol. It is designed for the synchroni-
zation of clients over TCP/IP. For the usage under Linux the V.24
output protocol has to be changed to XNTP (see chapter 5.3).
4.2.1 NTP installation
For easy installation of
NTP
you can find the shell script
make_
all.sh
on the CD-ROM at „tools\linux\get_ntp“. This script down-
loads
NTP
from the internet and compiles it.
Copy the folder „get_ntp“ to your hard disk. Now start
make_
all.sh
with the command
„-/make_all.sh“
. After the successful
application,
NTP
is compiled and ready for use.
End the installation with
„make install“
.
4.2.2 NTP configuration
NTP interacts with
EMC Prof NET (19“)
via the symbolic link:
/dev/refclock-0
. If
EMC Prof NET (19“)
is connected with
COM1
for example,
/dev/refclock-0
has to link to /
dev/ttyS0
(for
COM2:
/dev/ttyS1
).
If your Linux is based on Kernel 2.4 or older, you can create the
link with „
ln -s /dev/ttyS0 /dev/refclock-0“
.
Since Kernel 2.6
udev
administrates the In-/output device files.
To create a link to
refclock-0
automatically by
udev
, there has to
be a „rule“ for this link.
Change to the folder
rules.d
in the udev folder (e.g.
/etc/udev/
rules.d
) and open the file
50-udev.rules
. Add the following line to
the file. where the serial ports are defined:
KERNEL==“ttyS0“, NAME=“%k“, SYMLINK=“refclock-%n“,
GROUP=“uucp“
Please restart udev after this process.
# serial devices
KERNEl==“ttyS0“, NAME=“%k“,
SYMLINK=“refclock-%n“, GROUP=“uucp“
KERNEL==“tty[A-Z]*“, NAME=“%k“, GROUP=“uucp“
KERNEL==“pppox*“, NAME=“%k“, GROUP=“uucp“
Figure 12
50-udev.rules
file
