Ethernet Polling vs Broadcasting on an Embedded device
I have asked to design a test system for an Ethernet enabled weather
station. At this point, these weather stations are nothing but 2 PCs
running Linux on it and they constantly read weather related
through some sensors. Eventually they will be replaced with a miniature
embedded Linux device (yet to be designed!).
I have worked extensively with 1/2 duplex RS485 networks where we poll
device and then send an acknowledgment to the device. I am not too sure
what is the best way to handle an Ethernet enabled devices. The
engineers have agreed to change the Firm...Ethernet Device
I'm considering what kind of project I'd like to do for my next year
in college. I have an idea for creating a network host device that will
work on an Ethernet LAN. Obviously, my device would need some sort of
Network Interface Card in it.
Thinking about it for about 10 seconds tho, I realised that it might
be a *very* complicated job to create a Network Interface Card,
considering things like having to implement Carrier Sense Multi-
Access/Collission Detection. Not that I'm one to shy away from a big job,
but I plan on having this project done within a year :-P
...Ethernet over Ethernet
I don't know the reason why it is not possible to have an Ethernet
frame (ETH) directly encapsulated in an Ethernet frame (ETH).
Take care, I'm not talking about 802.1ah-2008 MAC-in-MAC, or
There is no Ethertype.
The only possibility is: ETH over MPLS over ETH, with the Ethertype
Thanks for your opinion,
On 04.06.2010 13:39 Michelot wrote
> I don't know the reason why it is not possible to have an Ethernet
> frame (ETH) directly encapsulated in an Ethernet frame (ETH).
> Take care, I'm not ...to poll or not to poll?
I am working on custom embedded linux-based machine
(Geode SC1100 CPU) and I have two problems to solve:
I want to 'copy' LAN activity LED status to front panel LEDs. I can
access front LED-s through /dev/gpioX devicebut the problem is how
to catch network activity without polling the status.
Currently I have implemeted that in loop by polling
/sys/class/net/eth0/statistcs/tx_packets but it takes a lot of CPU
time... Is there any other way to do it with some notifiers, events,
interrupts or something?
I have few switches connected to CPUs GPIO and I want...Polling, Polling, Polling (networking questions)
I'm wondering why my IBM T41 laptop (Windows 98 SE) is constantly
polling the network!
The network configuration: wireless and ethernet cards
It has been especially difficult to set up both to work together in SE.
This laptop has multi-boot with XP1 Pro and both cards work together
fine, so I believe the issues are not hardware related.
Currently the wireless is disabled, just working with the ethernet card
(Intel PRO 1000 MT Mobile). It seems so odd the card constantly polls
the network. I see the wireless adapter lights constantly flashing, the
wireless router lights constantly flashin...Ethernet I/O device
I hadn't noticed this before.
It's a bit pricey but might come in handy for the solder-challenged.
...Ethernet echo device
I'm an administrator of rather distributed network and I would like
to have opportunity to ping last-to-client device to see if the link is
up and the fault is at client's computer or cable.
I would like to ask, if there's something like 'ethernet echo dongle'
- a small device to be plugged into Eth equipment (hub, switch,
whatever) and being able to be pinged from network.
I know I may plug for example a dummy D-link router (~100$ at my
place) but perhaps there's something smaller and cheaper.
Pawel Kraszewsk...Poll on device fd
Can we do poll on device fd returned by CreateFile function call?
If yes, which is callback method in device driver(on win 2k) for poll ?
select() in Windows is for sockets only.
Maxim Shatskih, Windows DDK MVP
"Tejas" <firstname.lastname@example.org> wrote in message
> Hi All,
> Can we do poll on device fd returned by CreateFile function call?
> If yes, which is callback method in device ...[poll] what kind of devices do you own?
From the «plus one typewriter and two dictaphones» department:
Title: Poll: You Mainly Use Desktops & Laptops
Author: Christine Hall
Date: Thu, 27 Mar 2014 13:44:05 -0400
[image 1]It’s hard to remember that it wasn’t that long ago that we only had
a couple of choices to meet our computing needs. As recently as 2007, the
year before Obama was elected, someone looking for a new computer basically
could choose betw...Can 803 (ISDN-ethernet) work ethernet-ethernet?
e.g. as a broadband router, with an ADSL-ethernet modem?
I think the 803's four ethernet ports are all just a hub, not
Return address is invalid to help stop junk mail.
E-mail replies to peter4400@peter2000XY.co.uk but remove the X and the Y.
Please do NOT copy usenet posts to email - it is NOT necessary.
> e.g. as a broadband router, with an ADSL-ethernet modem?
> I think the 803's four ethernet ports are all just a hub, not
> addressable individually...
You can do nat on a stick, bu...Adding ethernet device driver
I added Realteck 81x59 ethernet card to my pc. And also i added the
driver. The problem is while iam doing communication betn linux and
vxworks system using udp protocal i can,t send or receive messages. It
is giving as HOST UNREACHble. These two systems are directly
connected using ethernet cable.
How to check in the target shell whether the driver is added properly
added are or not?
Thanks in advance
Can you ping the vxworks system? Does any communication between the systems
work, or is just UDP behaving badly?
What type of cable is connected between the two systems? ...Ethernet device in char mode?
I am looking for a way to put an ethernet device in a sort of
"character device" mode where I can simply read and write to it
without going through the TCP/IP stack. I am trying to test some
network hardware and right now I only care that what comes out of it
is identical to what went in to it. Does anyone have any ideas?
Jeff Ward wrote:
> I am looking for a way to put an ethernet device in a sort of
> "character device" mode where I can simply read and write to it
> without going through the TCP/IP stack. I am trying to test some
> network hard...device path for device
I have connected a new external tape device to my server , in another
server , I use the device path /dev/st0 for the internal device , but
I can't use the same device path for the new external tape device now
, are they different for internal and external device ? if yes, what
is the device path for external device ? thx in advance.
> I have connected a new external tape device to my server , in another
> server , I use the device path /dev/st0 for the internal device , but
> I can't use the same device path for the new external tape device now
...finding connected ethernet device
I have a laptop with an ethernet (eth0) and a wireless interface (eth1).
I'm using KNetworkManager to connect to networks, and in
Options>Configure>Notifications, have activated the Notification
"NetworkManager is now connected" to run a script ~/bin/connected.sh.
Thus, the script gets executed whenever I'm connecting to any network,
and handles starting some programs, e.g. ntpdate, synchronization of
This happens independently of what network interface the connection is
using. Now, I'd like to distinguish between ethernet and wireless (I...How do I communicate with 3 Ethernet devices
I am new to using ethernet and I need help writting a LabVIEW vi to communicate with 3 Omega devices. I need to open a connection to all 3 at the same time and read data from each. I am able to communicate with them individually using the TCP/IP vis (see attached vi) but I don't know how to communicate with all 3 at the same time.
Can anyone help?
Hello BertYou can simply replicate your code (copy and paste) so as to open multiple TCP/IP sessions to all three instruments as the same tim...Talking to an RS232 device over Ethernet
I would like to get data from an RS232 device. I am using a MOXA
serial/ethernet converter (works well in another app). The converter
is set up independent of VB. How do I code ASCII commands and pass to
the device? The converter has an IP address.
thanks for any help in advance
I've never used the MOXA converters but the ones that I have used
(Comtrol DeviceMaster, and others) have Winsock servers built into
them. You put a Winsock in your program and communicate that way. As
far as the ASCII commands are concerned, I would think that you'll
have to read the manuals that came wi...Polling HW Devices with Linux
I am part of a team project in which we are requested to design a thermal
sensing system. We are asked to use Linux as the primary OS. The Thermal
Sensing Hardware is already designed. It is a pollable device (meaning you
send a request and it will give you a reply).
I am wondering if there is a Linux Messaging or Queing method that I could
use straight of of the box, Or is there a Kernel component that could do
such a Send/Receive/Reply. I have used IBM's MQs in the past but for this
task I don't think it is a viable option. I am really looking forward to
kn...How to poll multiple devices in kernel ?
I'm a beginner in driver and module programming, and I need some help:
I designed a driver that need to listen at multiple devices (network
device, serial device, USB device) for incoming data.
Once received, that data should be accessible to user space through
the "read" function.
That's why I cannot use the poll/select functions from user space.
My first idea is to make a kernel thread for EACH device that do a
blocking read. When data comes, read returns and fills a global buffer
(protected with mutexes). Do you think it is a good idea?
S...Device to device calling
I am looking at a VOIP (high quality) for device to device calling between
UK an Southern African Countries.
It should however allow for device to landline PSTN. Any ideas for a good
quality equipment. I have used Yap jack but call quality is very poor.
...Talking to an RS232 device over Ethernet
Does anyone have any experience sending ASCII commands over ethernet,
through an RS232/Ethernet converter to an RS232 device?
I am coding in VB and would like to know where to start.
...Ethernet/Fast Ethernet/Gig Ethernet Distances over media
I was hoping someone could help me out here...
Has anyone seen a chart/matrix which shows distance limitations for
Ethernet, Fast Ethernet and Gig Ethernet over the various media types? I
have googled for the information and found what I need for Ethernet, but not
as a single chart. Also, there seems to be some conflicting information out
Thanks for your time
In article <email@example.com>,
"Chris Harvey" <firstname.lastname@example.org> wrote:
> I was hoping someone could help me out here...
>...Specifying ethernet device assignments
I'm upgrading a set of servers from RedHat 7.3 to Fedora Core 2
(doing a fresh install), and have run into a complication on systems
with multiple identical ethernet devices.
I've got 3 on-the-motherboard ethernet ports on the server in question -
two Intel Gigabit ports using the e1000 driver, and a 100 MB port using the
In a default installation, the system assigns the e100 to eth0, and
the e1000s are eth1 and eth1. By editing /etc/modprobe.conf and running
mkinitrd, I can "swap" the eth0 and eth2 definitions, making eth0 one of
the e1000 ports,...question on Ethernet Device driver
1) Iam working on Philips LPC 2292 controller board, Ethernet
controller is Rtl8019 and Iam testing Rtl8019 driver on linux 2.6
Kernel.I have few Doubts.
2) If at all if a single packet comes and sits in Rx Buffer. Whether
my ethernet controller immediately raises an Interrupt or it wait for
Few seconds or milliseconds for another packets to sit in Rx Buffer
before it raises an Interrupt.
3) If at all If ISR is Executing and if Before copying a packet from
Rx Buffer to local Buffer, if few packet comes to Eth controller,
will respective packets sits in Rx Buffer or pack...cannot ping local ethernet device
Hi TCP-IP gurus,
I have a local ethernet device configured with the IP address 10.3.0.1
and a netmask of 255.255.0.0 . When I try to ping the device, the
ICMP echo messages get routed to the local loopback interface instead
of the ethernet device itself. Is there a way to force the local
routing table to allow the packets destined for 10.3.0.1 to actually
reach that IP address instead of the 127.0.0.1 loopback interface ???
Here is the routing table configuration.
0x4 ...00 ff f6 7a a8 30 ...... TAP-Win32 Adapter V8 - Packet