pdl-tcpip Protocol

[Eamon Doherty]

Hi,

perhaps someone has done this before is so I’d be grateful for some enlightenment.

I’ve an interface to send messages to a third party app. with no encoding or encapsulation. The ACK from the app. uses MLP.

The standard mlp_tcp.pdl works fine for the ACK and I can code a basic PDL to transmit messages with no encapsulation but how to combine these within a single PDL

Topic

[Jim Kosloskey]

Eamon,

I was once faced with a similar situation.

We informed the vendor that they eeded to comply with the MLP both on messages sent and messages received.

After some arm twisting the vendor ‘got religion’ and complied.

So unfortunately I do not have a PDL solution for you but in my opinion the third party needs to get their act together.

After all if they can use MLP for acknowledgment they should be able to handle it on received messages.

Besides, if you have no encapsulation on the messages you are sending, how can anyone be sure they get the entire message and only one message?

My .02 worth…

Jim Kosloskey

email: jim.kosloskey@jim-kosloskey.com 30+ years Cloverleaf, 60 years IT – old fart.

[Charlie Bursell]

Won’t work!  With no encoding or encapsulation how would you know when you have received a complete message?  We can deal with new-line delimited ut it will give you fits.  How do you resync if you get out of sync?  That is why there is normally start and end characters.

I think your vendor is not well versed on communicating via TCP/IP

[Eamon Doherty]

Jim, Charlie,

thanks for the replies, I didn’t think this would be possible.

As a bit of background the vendor uses know strings within the message I send to parse the message. I don’t agree with this approach but this is how they work. I’ve gone back to the supplier to ask them to reconsider.

[Robert Gordon]

HI all;

 The question ask to why the vendor can’t send control characters is because, (Which is a wild guess at this point!!!):

a)  The vendor doesn’t know how to code in the language he has selected for coding i.e. VB.  Microsoft sent out manuals with not all the information so coders use it like a bible; even though Microsoft has sent out patches which make the manuals obsolete.  The vendor should use the website for more current information.

b)  The coding for tcp/ip connections comes from a third-party (free demo license) and the vendor doesn’t want to spend the money for the library.

c)  The vendor didn’t do any coding except use a 3gl (Third Generation Language), which uses a drag and drop metaphor and creates neat applications, but is limited when it comes to coding.  This kind of coding you should avoid as most virus checkers can cause run-time errors.

[Author]

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