serial over TCP

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DaisyDuke

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Hi all,
I am writing an application that will run on a ppc2003 pda and that will act as a tcp server to interact with few serial devices over ethernet.
So far I tested the code desktop side, using a com port redirector over ethernet, so that in basic4ppc I just need to handle different COM ports without warring about handling TCP communication.

I was unabled to find a serial to ethernet redirector for windows mobile. Does anyone know one possibly freeware?

A more elegant way to do the job it would be to write everything with basic4ppc, but I can't figure out how to combine the serial controls with the TcP communication.
Any hints are appreciated?

thanks
 
D

DaisyDuke

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Hi Agraham, thanks for your interest in my issue..
Well I think I need to use the serial library because I am reading a measurement from a digital caliper with serial interface, and the data request is done by triggering the DTR pin. If it was just a matter of writing/reading data yes I agree that the network library is enough. But how do I trigger the DTR PIN?

Just for telling you what the all project is about, I'd like to use a pda to feed a CNC machine with several measurements taken by digital gauges. I could get digital gauges with a USB interface but then I will have to stick with a dedicated PC for dealing with drivers. Therefore I thought to have everything serial since the CNC machine also communicates easily throught its serial port.
The problem is that a PDA has only 1 real COM port, so I cannot connect all the serial devices. That's why I need more COM ports.
I thought to overcome that by using a multi port serial to ethernet converter, the serial devices are TCP clients, and the pda is the TCP server.
So far so good until it comes to deal with triggering the DTR pin :BangHead:
 
agraham

agraham

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I thought from your description that you wanted to emulate COM ports to communicate over TCP, not originate data from them for onward transmission.

I am afraid that don't have any good ideas as to how to connect several serial devices to one PDA. In the old days I might have knocked up a PIC based controller and some UART chips to do the job. The other obvious way is to use one PDA per caliper and talk to them individually over the WiFi network from another PDA feeding the CNC machine. In a commercial environment the cost of the additional PDAs might be outweighed in the time saving of the ease of implementation.
 
agraham

agraham

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I don't understand how that software can help. Isn't the problem the fact that you have multiple digital calipers each with a physical serial port and the pda you want to use only supports a single physical port so can only connect to a single caliper?
 
D

DaisyDuke

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Well it creates virtual com ports "inside the PDA" redirected over the LAN to real ports. The attached sketch might help the idea...
This is my approach since I have an old Lantronix 16P Serial to Ethernet converter and several PDAs to play with.
 
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M

mjcoon

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DaisyDuke said:
Well it creates virtual com ports "inside the PDA" redirected over the LAN to real ports. The attached sketch might help the idea...
This is my approach since I have an old Lantronix 16P Serial to Ethernet converter and several PDAs to play with.
Click to expand...

Surely if your calipers actually implement enough of standard RS232 serial then the device you label "server" will communicate with them OK. If not, I don't see how anything you do at the PDA end will make any difference.

How, for instance, does the "server" device set up the serial parameters for each of the physical RS232 ports?

Mike.
 
D

DaisyDuke

Member
Licensed User
Every port of the server device can be configured indipendently via webserver to meet the connected serial device specs, the standard RS232 parameters. Then the port is accessed through a tcp client to server connection.
bye
 
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