Lost on LAN line

[cncmachineguy]

I have a need to use the ethernet port for I/O connection to the outside world. I have no need to gain access to any networks, I just want to be able to send and recieve data to a PC. Think of this like a parallel port.

I have been reading all the posts in this section, but must admit I know nothing about ethernet connections. Is this something that can be done with 1 of the many chips referred to through this section of the forum?

I am sorry to sound vague, but I really don't even know what to ask to get started asking questions. I see there are serial to ethernet adaptors, can I assume this would act like a rs232 to USB adaptor? In other words the PC would think its talking to the network card, and the PIC would think its talking to the serial port? I don't want to send AT commands.

My device would be a slave, all comms would start from the PC. For instance the PC would send a read data command, and the PiC would respond with the packet of data. OR, the PC sends data, and the PIC grabs it and does what it needs to with it.

Here is a link to what I want to acheive:
http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Etherlab

Thanks for reading this LOONNg post.

[mister_e]

I think the easiest way to acheive this is to use the Charron module, or some alike. They are plug and play, and you control them with simple Serial command. You can even use Hyperterminal for that
http://www.hw-group.com/products/charon1/index_en.html
they also provide some code example for various PC language.

Sure enough there's more than charron one on the market, but I don't know... really need to refresh my stock for that one day...before
http://free.timeanddate.com/countdow...05-21T18:00:00
Time goes by too fast

[gadelhas]

HI;

I recomend you TIbbo Module. Its very easy to use.
This;
http://tibbo.com/products/modules/minimo/em500.html

Or this;
http://tibbo.com/products/modules/em1000.html

It dependes how much I/O-RS232 Ports do you intend to use

[cncmachineguy]

Oh thanks Steve. More to say now, the PC side will be handled by linux/EMC2. On the PIC side, I need to get faster then 115K - I think. Really best case is a parallel output. So I guess I don't actually want the serial->net, I guess I want PIC->net. So I need the preprogrammed interface chip and not the whole converter. Assuming there is such an animal.

LOL on the countdown

[dhouston]

It's not really clear what you want to do but the WIZ110SR or WIZ812MJ from WizNet are some of the lowest price adapters around.

OTOH, if you are planning to use an ethernet capable PIC, you can find some code here for that.

[Charles Linquis]

I use Lantronix XPorts and MatchPort AR parts. They aren't too easy to setup from the "serial side" (it is doable, however), and setup from the "network side" is a breeze. They work well and the nice thing about an XPort is the small size. Just supply 3.3V and a serial connection and you are good to go. They are about $50 each in small quantities.

[gadelhas]

I use Lantronix XPorts and MatchPort AR parts. They aren't too easy to setup from the "serial side" (it is doable, however), and setup from the "network side" is a breeze. They work well and the nice thing about an XPort is the small size. Just supply 3.3V and a serial connection and you are good to go. They are about $50 each in small quantities.

Also agree, very good the Lantronix!!!

[cncmachineguy]

Ok, let me give this another go. In the beginning there was the ISA bus. It was quite simple to make a card to plug into it and have I/O using an 8255 or simular. Then that was replaced with the PCI bus. Not near as useful from a homebrew interface card. But we still had the parallel port. If used in EPP mode, quite high speed could be had using a pretty simple homebrew card. I have a card now that gives me 64 I/O lines, all through the pport. This is all needed for my current CNC control.

But the parallel port is going away also, so we are left with few choices if we want to use our computers for anything other then surfing the net or playing games. we have:

USB - Great interface but not realtime. Service could be as long as 10mSec delay. No good for machine control
FireWire - Don't know much about it, may be great but not widely available
PATA - I am looking into this as it is based on ISA bus. But not too motivated as that seems to be vanishing also.
FDD - same as PATA
SATA - may be viable, but most likely too much trouble.

Brings us to the NIC. It has been used for what I want to do, including available drivers for the PC side of things. (The link I posted in the first post shows a finished product of that which I desire). So for me, that is the hard side and its done already. I just need to come up with a suitable way to have a PIC talk to a NIC. In a fashion much faster then 115K. Now the ethernet capable PIC sounds VERY intresting. I will surf that a bit. Keep in mind I have NO idea what it takes to talk to a NIC. In my mind I think it must be pretty hard as I have read things like TCP/IP stack and UDP protocal. Lots more stuff I don't even want to think about.

[cncmachineguy]

Been over to the mother site. I seems that the 18f87j60 may be just the ticket.

[ScaleRobotics]

Bert has me interested in this stuff as well. Here are some links for for the EtherCat protocol, and for a slave product by Beckhoff that works with a PIC chip and C code.

EtherCat: ethercat-1.5-6129a5f715fb.pdf

EtherCat slave info: http://download.beckhoff.com/downloa...L9800_V1i1.pdf

EtherCat EL9800 Board: http://www.ethercat.org/en/products/...2DEABC1474.htm

EtherCat EL9800 Board PDF: http://download.beckhoff.com/downloa...00e_Ver3.0.pdf

[cncmachineguy]

Ooh good stuff Walter!! Thanks for that. Not sure if I am reading correctly, but it seems the pic stuff has a 24 for them comm part then an 18 for the brain? Maybe something about the PHL(?) or physical hardware layer or something like that. Man there is a lot to know about this.

[ScaleRobotics]

I guess the EL9800 microchip based board is designed to accept the "Postage Stamp" board by Beckhoff, which does the ethernet handling with 2 Micrel and a proprietary EL-CAT (U400) chip. Yeah, the PIC18 reference has me confused too, as it sure looks PIC24 ish to me. Maybe there was an earlier board with a PIC18??

[cncmachineguy]

I had hair on my head as of yesterday, but now I seem to have it mostly pulled out. I am sure glad I have you guys here helping me with this. There is LOTS to read this weekend.

[cncmachineguy]

@ Dave (macracket), missed your post before, must have crossed posted. I looked quickly at the link, is that a SBC or something to hook to my SBC?

[mackrackit]

Can be a single board, but the cool thing about the 104 form factor is they are stack-able if you need to expand the system (add more stuff).
http://en.wikipedia.org/wiki/PC/104
And because they are popular in industry they will commonly have RS232 and LPT built onto the main (first) board and run in high temperature environments.

[cncmachineguy]

Its not often that this happens, but after careful consideration I have decided this is far beyond my reach at this time. There is a lot of things to learn about ethernet, etherCat, and how it all works together.

Thank you all for the help!