Lost on LAN line

[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]

I have No problem with my desire to explain what I am trying to do, but clearly have a huge problem actually explaining it. Thanks Henrik for bringing some clarity to this for me. Here goes my next attempt:

This will be a direct 1 to 1 connection between my I/O card and the PC. So I am assuming there should be no collisions or contention on the bus.
The intention is this:
every 20uSec I want to send 4 bytes of data to a PIC, and receive 4 bytes back. So every 20uSec, there needs to be 8 bytes transferred of actual data.



The PIC will use the 4 bytes in 1 of several ways:

• simplest setup is a stepper driven machine. In this case the PIC will just transfer the bytes to ports as output.
• next case is servo driven machine. In this case hardware PWM will be updated to reflect the new values just received. So the PIC just transfers bytes to registors (I haven't given much thought to this case as my current needs are for stepper control)

In either case, there should be no real processing on the PIC side, just Move the data and wait for the next packet.

For the 4 bytes going back to the PC, this is just read a port and send the data. I think the PIC may be always 1 packet behind on the sent data. I am thinking after every transmission, a buffer is updated with new port data then waits for the next packet request from the PC.

There is NO motion control in the PIC itself, this is all done on the PC using EMC2 software. Step/DIR generation is all done on the PC. Each bit of 1 byte is the step value for 1 driver.

Hopefully this makes things at least a little bit clearer.

Thanks Henrik for the card offer, as yet I would have NO idea what to do with it, so I fear it would be a waste for me to accept it.

As for the choice of PIC, I feel like the idea of built in ethernet controller may solve the problem for me, but I don't know. I am clearly in the dark as to what it takes to have a successful exchange of data between a NIC and a PIC. If I need to use something like PIC32MX695F512L, then so be it. The program for this should not be intense, at least once the data has been received. I would prefer to use something more like 18F97J60, but just to keep it in the PBP family.

In a servo set-up, the amount of data may go up. But I can't see more then 8 bytes each way.

[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.

[dhouston]

Ethernet is not necessarily realtime. You can have very lengthy delays unless you are planning a one-on-one connection with no possibility of collisions, retransmissions, etc.

While I've been retired for 20+ years, I've been in a few thousand manufacturing facilities. (I ran the US subsidiary of a French machine tool builder.)

Are you wanting to control a CNC machine from a PC? Is the PIC going to be on the CNC machine or PC end of the link?

[Archangel]

Hi Dave & Bert,
Dave
I am standing on the back of Bert's calves looking over his shoulder,(well figuratively anyway) watching as I want/need to do the same things, and am pretty sure he wants the PC to directly control the CNC as opposed to drip feeding it. After a while it is impractical to use ancient PCs as they wear out and fail too. New PCs can be had for 4-500 USD and that beats going Salvation Army shopping. but as Bert stated the ECP and other options have been killed (Thank's Mr. Gates).
Bert,
Controller cards which have Parallel ports are still available for pci bus.

SYBA SD-PCI-1P DB25 PCI
Frys # 5370288