Diagnose Connection Problems

Introduction

If you are having problems connecting to a Fernhill SCADA Server, then you should follow these steps to try and identify the cause of the problem:

Check the Fernhill SCADA Server is running

The Fernhill SCADA Server runs as a Windows Service. To check the Fernhill SCADA Server is running:

  1. On the computer running the Fernhill SCADA Server, open the Control Panel.
  2. Open Administrative Tools.
  3. Open Services.
  4. Scroll down until you see the entry for Fernhill SCADA Server:
    Fernhill SCADA Server shown in the services list
  5. Check the Status is Started.

    Note: If Status is not showing Started, open the service Properties and try to start the service. See Managing the SCADA Service for more information about managing the Fernhill SCADA Server Windows Service.

Check the Fernhill SCADA Server is listening on the correct TCP/IP ports

The Fernhill SCADA Server accepts connections from client applications on TCP/IP ports 20295 and 20296. To check the Fernhill SCADA Server is listening on these ports:

  1. On the computer running the Fernhill SCADA Server, open a Command Prompt with administrator privileges.
  2. At the command prompt enter this command:

    netstat -naob -p TCP

  3. Check the results contain entries for the Fernhill SCADA Service FHSvrService.exe listening on ports 20295 and 20296:
    Fernhill SCADA Server listening on ports 20295 and 20296

    Note: If another program is listening on either of the ports there is a port conflict. Try to re-configure the other program to remove the port conflict.

Check a Firewall is not Blocking the Fernhill SCADA Server

The Fernhill SCADA setup program automatically adds rules to the Windows Firewall to grant network access to the Fernhill SCADA Server. It is possible another user or program has modified, or removed, these rules which is preventing programs connecting to the Fernhill SCADA Server.

To check the Windows Firewall Rules:

  1. On the computer running the Fernhill SCADA Server, open the Control Panel.
  2. Open Windows Firewall.
  3. Click on Allow a program or feature through Windows Firewall
  4. Scroll down the list and check there is an entry for the Fernhill SCADA Server:
    Fernhill SCADA

    Note: If firewall rules are missing try to rerun the setup program in repair mode to reinstate the firewall rules.

It is possible another firewall product is blocking access. This could be an additional software product installed on the PC running the Fernhill SCADA Server, or could be a network device performing the function of a firewall. If you have additional firewalls you need to configure them to allow the PC running the Fernhill SCADA Server to accept connections on ports 20295 and 20296.

Try and connect locally

You can run the operator interface on the same computer that is running the Fernhill SCADA Server to check the whether local connections are possible:

  1. On the computer running the Fernhill SCADA Server, start the operator interface using the method described in Start the Operator Interface From the Windows Start Menu.
  2. Click on Connect to a Fernhill SCADA Server.
  3. Enter localhost in the Computer Name field.
  4. Click OK. Confirm the default graphic page opens.

    If the Fernhill SCADA Service is running, and the Fernhill SCADA Server is listening on ports 20295/20296, and no firewall rules are blocking ports 20295/20296, there may be a software problem. Submit a bug report to support@fernhillsoftware.com. Try and include the server log file for the connection attempt.

Run a ping test from a remote computer

You can run a ping test to check the network connection between two computers. A successful ping test will show you have a working network connection between two computers. A failed ping tests does not mean the the network connection is not working. A ping test can fail because firewall rules are blocking ICMP Echo requests.

To run a ping test

  1. On the remote computer open a Command Prompt.
  2. At the command prompt enter this command:

    ping a.b.c.d

    Where a.b.c.d is the IP address of the computer running the Fernhill SCADA Server.

If the ping test succeeds you will typically see output like:

Pinging 192.168.1.218 with 32 bytes of data:
Reply from 192.168.1.218: bytes=32 time<1ms TTL=128
Reply from 192.168.1.218: bytes=32 time<1ms TTL=128
Reply from 192.168.1.218: bytes=32 time<1ms TTL=128
Reply from 192.168.1.218: bytes=32 time<1ms TTL=128

Ping statistics for 192.168.1.218:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

If the ping test fails you will typically see output like:

Pinging 192.168.1.218 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Ping statistics for 192.168.1.218:
    Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

If the ping test fails check the Windows Firewall on the computer running the Fernhill SCADA Server allows ICMP Echo Requests. The Microsoft Technet article Nobody Can Ping My Computer provides details how to do this.

Further Information

Operator Interface

To more information about the Operator Interface.

Fernhill SCADA Server

To learn about the Fernhill SCADA Server.

Glossary

For definitions of the terms used in Fernhill SCADA.