Socket Programming

[Graham Wickens]

have USB device that "Talks" to software running on my machine. I want to be able to read this data and then do a lookup on a DBF and then display relevant information.

What I have found out so far:

The socket outputs the messages on IP "127.0.0.1" socket 30003 in a CSV format, with a carriage return and lifefeed (ascii 13 followed by ascii 10) at the end of each message.

Not all lines will have the same number of fields, and not all fields will have the same meaning. Basically, the first field has the message type, and then from that I know how many other fields there will be and what they will contain.

I want to ignore any message types that aren't ones I want.

the records I want to read are formatted as shown below:

Field 1: AIR
Field 2: [null]
Field 3: SessionID
Field 4: AircraftID
Field 5: HexIdent
Field 6: FlightID
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged


I then want to do a database lookup on field 5 [HexIdent].

Can some tell me whether this is available in A5V7 as I see some "socket" commands. If so how do I go about doing it.

open socket.
if field1 = "AIR" get Field5

query on HexIdent field [24-bit-binary code represented in 6 character Hex].

display result.

go back to reading the socket for next query.

[Marcel Kollenaar]

Re: Socket Programming

Graham,

In the Alpha Five helpfile I read:
Syntax: <SOCKETS> as P = SOCKETS.OPEN( Hostname as C, Port as N, Mode as C [, ConnectTimeout as N ] )

Description
<SOCKETS> A pointer to the open connection.

Hostname: The hostname or IP address of the remote host to connect to, such as "www.alphasoftware.com".

Port: The TCP/IP port to open the connection on.

Mode: The socket mode:

"C" = Client; "S" = Server; "L" = Listener

ConnectTimeout: Optional. The time-out period in milliseconds.

Description
The SOCKETS.OPEN() method establishes an Internet connection. The method creates a blocking call, which means that the system will be unresponsive until either the socket is successfully opened or ConnectTimeout milliseconds have elapsed.

"C" and "S" mode socket open calls are blocking. This means that a client or server socket open call will not return until the connection is successfully established or the connection attempt is aborted by the operating system. This can cause Alpha Five to appear to be hung while a connection is being established, as the operating system timeout period is typically 8 minutes.

ConnectTimeout, if specified, is the time in milliseconds to wait before aborting the connection attempt and allows the operating system timeout to be overridden.

In your case:

<SOCKETS> as P = SOCKETS.OPEN("127.0.0.1", 30003, "L", 10000 )

and of course all the other sockets commands such as <SOCKETS>.READLINE() etc. There are simple examples in the helpfile.

I don't know for sure but the other device might miss data if you tap on the 30003 port.

Regards,

Marcel

[Graham Wickens]

Re: Socket Programming

Thanks Marcel,

I assume I dont need to setup a server for this one off project?

[Marcel Kollenaar]

Re: Socket Programming

Graham,

That's a very good question. :) I honestly don't know but with the next simple test I think you can use the commands without setting up an server.

dim sock as P
sock = sockets.open("127.0.0.1",80,"L",1000)

?sock.close()
= <No data returned>

I didn't get errors that I need a server or anythings else. I suspect the USB is the server and your program that uses the data is the client.

With the <sockets>.peek(1024) command you can look at the first 1024 bytes of data without removing them. The problem is to get the socket address that already is opend by the client program. If you open a socket on the same ip and port I think you will get an error. I did when I opened the same ip a second time...

At the moment I deduct common knowledge. Maybe some Guru from Alpha can help you further.

[Graham Wickens]

Re: Socket Programming

I tried a simple test using socket.open() but it needs to have the socket to itself, does not want to play, says socket already in use. This being the case, I have come across a PHP script than CAN share the socket and read data, so I think I will have to self teach myself some php to be able to modify this script to achieve my aims, not that I have ever programmed in PHP either!!
thanks for your time.

[Marcel Kollenaar]

Re: Socket Programming

;)

[Lenny Forziati]

Re: Socket Programming

It sounds like your USB device is acting as a server on the socket, which is the expected behavior. In that case, you should be opening the socket in Alpha as a client socket using the "C" flag.

[awj]

Re: Socket Programming

Hello Graham;

What type of USB device are you using? I'm wanting to use a USB connection to a Glucometer to grab data from it to create possibly an imported CSV or DBF file, which I can then manipulate and append into the A5 application. I'm wondering if this might work.

Would the SOCKETS functions achieve this? Have you had success with your device?

Very interested to find out your results!

regards, awj :)

have USB device that "Talks" to software running on my machine. I want to be able to read this data and then do a lookup on a DBF and then display relevant information.

What I have found out so far:

The socket outputs the messages on IP "127.0.0.1" socket 30003 in a CSV format, with a carriage return and lifefeed (ascii 13 followed by ascii 10) at the end of each message.

Not all lines will have the same number of fields, and not all fields will have the same meaning. Basically, the first field has the message type, and then from that I know how many other fields there will be and what they will contain.

I want to ignore any message types that aren't ones I want.

the records I want to read are formatted as shown below:

Field 1: AIR
Field 2: [null]
Field 3: SessionID
Field 4: AircraftID
Field 5: HexIdent
Field 6: FlightID
Field 7: Date message generated
Field 8: Time message generated
Field 9: Date message logged
Field 10: Time message logged


I then want to do a database lookup on field 5 [HexIdent].

Can some tell me whether this is available in A5V7 as I see some "socket" commands. If so how do I go about doing it.

open socket.
if field1 = "AIR" get Field5

query on HexIdent field [24-bit-binary code represented in 6 character Hex].

display result.

go back to reading the socket for next query.

[Graham Wickens]

Re: Socket Programming

Sorry Andrew,

I cant help, programming sockets and stuff is all new to me, so cannot really help you.

[Marcel Kollenaar]

Re: Socket Programming

Hello Graham;

What type of USB device are you using? I'm wanting to use a USB connection to a Glucometer to grab data from it to create possibly an imported CSV or DBF file, which I can then manipulate and append into the A5 application. I'm wondering if this might work.

Would the SOCKETS functions achieve this? Have you had success with your device?

Very interested to find out your results!

regards, awj :)

Hello awj,

I don't know if this reply will help you but I recently bought a little device with an USB connection. The smart part of it is that the vendor of the USB chip made a driver in such way that someone can access the USB port as an COM port. Virtual COM port (VCP) drivers cause the USB device to appear as an additional COM port available to the PC. Application software can access the USB device in the same way as it would access a standard COM port.

This is remarkable because if you programmed all your software to communicate with a serial com device you don't have to reprogram all your software for USB. Problem is that not every supplier of USB (hardware) chips have this kind of driver type; a virtual driver or a dll version that can be accessed by API-calls and in both cases in range of Alpha Five.

The other way around is also possible. e.g. You have a normal serial device and has the next connection.

PC->COM1<--->serial->hardware

If you have hardware with a serial interface you only have to add this chip to create a USB version of it. The only thing it does is:

PC->VCOM->USB<--->USB->serial->hardware

I don't know if you can get the hardware specs of this gluco device and try to find out the manufacturer/vendor. If it is your own and dare to open it you can write down the IC type and number and look around on the net if the manufacturer has virtual drivers for it or a legacy dll.

However there is one catch. In this case USB is just a kind of "host-connection". Behind the USB chip in the device everything is serial again.

[awj]

Re: Socket Programming

Hello Marcel;

Can we access this "COM Port" with Alpha Five somehow if I had a VCP driver?

thx, awj

[Marcel Kollenaar]

Re: Socket Programming

Hello Marcel
Can we access this "COM Port" with Alpha Five somehow if I had a VCP driver?

thx, awj

Yes, to the outside world it just looks like a normal COM port. I've seen posts here that there is an ActiveX software package to do the serial communication. This should do the job if you have such virtual driver. But the point is to see if the vendor of the USB schip in the gluco device has such driver for it. Each USB chip is different and there is no such thing as a general driver that covers all. The only vendor up till now is FTDI.

The chip in the device I bought is an FT232BL


Very important! The drivers on the FTDI site are only usable with the chips FTDI produces. You have to look at the vendors site of the chip that your device uses.

BTW In the next upcomming weeks or month (depends on how much time I can spend on this subject) I'm planning to try to communicate with an network device with A5 datagrams (UDP net message, I think) and have to use sockets. If there is something to mention I will :).

[Marcel Kollenaar]

Re: Socket Programming

awj,

I read some of your older posts. Is it correct that these post did not solve your problem? And if so what is the real problem?

I'll start a new topic....

[Graham Wickens]

Re: Socket Programming

Hello Marcel,

finally got the code to read the data coming from socket 30003:

dim bs as p = sockets.open("127.0.0.",30003,"C")
dim bsOutput as c
for i = 1 to 10
bsOutput = bs.readline()
trace.writeln(bsOutput)
next I

That is the easy part, Now I have to workout how to continually listen to the port and do the database lookups at the same time.

[Marcel Kollenaar]

Re: Socket Programming

Thanks Graham for the feedback! :)