Why Is My Client To Server Connection Not Working?

The Client to Server connection relies on correct TCP/IP, Security, DCOM, and ODBC configuration. If any of these are not right then The Enabler Client will not operate correctly. Check the following items to troubleshoot your problem.

TCP/IP

First is it necessary to establish that the TCP/IP network is working correctly. This can be done using the ping command. Open a command prompt on the Client machine and type the following command:

    ping 'enabler server name'

If this command works correctly you will see several lines like this:

    C:\>ping server1
    Pinging server1 [191.192.1.2] with 32 bytes of data:
    Reply from 191.192.1.2: bytes=32 time<10ms TTL=128
    Reply from 191.192.1.2: bytes=32 time<10ms TTL=128

If the ping command does not work, check the following:

  1. If you see the following error:

    The name specified is not recognised as an internal or external command, operable program or batch file.

    Ensure that TCP/IP is installed. The ping.exe program is installed as part of TCP/IP. Once installed, check the configuration as described in 2 (below), and then try to ping the server again.

  2. If you have any other error when trying to ping the server:

    • Check that both client and server Ethernet cables are connected.
    • Check that the "link" indicator is lit on both client and server network cards.
    • If using an Ethernet hub/switch/router, ensure it is configured to allow the two machines to communicate.
    • Check that both client and server have an IP address, by typing "ipconfig" at a command prompt.
    • Try setting both machines to a static (fixed) IP address instead of using "Automatically obtain an IP address" (DHCP). Normally you can use 192.168.x.x addresses safely.

User Access Rights

Check that the client application runs under a UserID that is setup on both client and server computers. Both the username and the password must match.

A simple test that the client has access to connect to the server is to type the following command:

   net view \\'enabler server name'

If this command reports that you do not have access, then go back and check that the UserID and passwords are correct.

DCOM Configuration

On each computer accessing the Enabler, including the server, run the Windows DCOM Configuration Utility, DCOMCNFG, from a command prompt or the Start - Run... menu.

Windows NT/2000:

DCOMCNFG on NT/2000

Select the entry for Enabler Pump Server, and click properties.

Windows 2003 (SP2) / Windows XP / Windows Vista:

Expand the explorer on the left-hand side to see the list of registered DCOM servers as shown below:

DCOMCNFG on XP

Right click on Enabler Pump Server and select Properties...

Client Computers

Click on the Location tab.

DCOMCNFG - properties

  • Make sure that "Run application on the following computer:" is checked
  • Enter the name of the computer running the Enabler Server in the box underneath.
  • Make sure "Run application on this computer" is not checked.
  • Make sure "Run application on the computer where the data is located" is not checked.

Server Computer

Click on the Location tab.

DCOMCNFG - properties

  • Make sure "Run application on this computer:" is checked
  • Make sure "Run application on the following computer" is not checked.
  • Make sure "Run application on the computer where the data is located" is not checked.

Note: For servers running Windows Vista, Windows XP or Windows Server 2003 (SP2), refer to our FAQ page What security settings are required for Enabler Server PCs running WinXP SP2 or later? for aditional steps.

Test DCOM Configuration

To test that your machines are configured correctly, we recommend you use the demonstration program pumpdemo.exe in the Enabler directory.

Version

Ensure that the Enabler client module incorporated into the POS application is the same version as the Server part of The Enabler software. If there is a mismatch, the application will work partially or not at all.

Remember that you won't see any pump icons on the client until you have setup pumps using Enabler Configuration.

ODBC Configuration

Depending on the design of the Point of Sale, this may not be required on client computers.

Open Control Panel - Administrative Tools - Data Sources (ODBC) (ODBC Data Source Administrator on Windows NT).

Click on System DSN and check that there is a data source named "Enabler" that points to the Enabler Server machine. If not, run the "ODBCCnfg.exe" Enabler utility to add one.

You can also add a data source manually. It should use "With SQL Server authentication...", unless you have specifically changed the system configuration.

SQL 2005 Express Edition

SQL2005 Express Edition doesn't allow null or blank "sa" passwords unlike MSDE2000 or SQL Server 2000. Thus you may need to enter the default "sa" password in the System DSN to connect to SQL2005 Servers.


© 2008 Integration Technologies Limited
Last revised Wednesday, 04-Nov-2009 18:41:46 EST