Link to home
Start Free TrialLog in
Avatar of sroughley
sroughley

asked on

[URGENT] Help with com port communication...

Hello all,

I am having some problems trying to communicate with a fuel-pump system via a com port. Currently users are accessing the system via HyperTerminal, which works perfectly, but we now need to automate their fuel transaction system. We have been trying to use a third party library that can be downloaded from: http://www.codeproject.com/dotnet/DotNetComPorts.asp to perform the necessary communications. We can use this library to initiate basic communications with the fuel system, but it does not appear to work correctly. When users use HyperTerminal they enter the command 'hello' and this results in the prompt 'ENTER MAIN PASSWORD' (though sometimes this results in the message '** PRIVILEGED COMMAND **' and the users will need to re-enter the 'hello' command) where the users then enter the password and receive the message 'hello!'. They are then able to enter in various commands to communicate with the fuel pump system.

When we try to do the same from a VB.NET application all we receive is the '** PRIVILEGED COMMAND **' message and some junk data which sometimes states that there was an error, i.e.
...
** PRIVILEGED COMMAND **
>1?sbi_iCQgsrfwR%VPd9tjq`iw(VRp
--error
>
...
We can not get past this.

I need some pointing in the right direction now as I have never done anything like this (comm ports etc) before and unfortunately we don't have any time to spend researching this. Also, there is the added difficulty that this can only be tested on-site (which is remote to say the least and we are only there on rare occasions) so we really need a plan of action for our next visit.

Have any of you guys any experience with this sort of thing or any ideas as to where I might be able to look to find alternative solutions?

I thank you in advance for your time,

Stephen.
ASKER CERTIFIED SOLUTION
Avatar of AlexFM
AlexFM

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of sroughley
sroughley

ASKER

Thanks for your fast response! I've downloaded several different sniffers and will try them out and let you know how I get on.

Thanks again!

Stephen.
You're a star! We used a serial port sniffer and found out that there are some extra characters that need to be sent to activate the commands!

Thank you for your help!

Stephen.