Itís possible to use DirectSOFT32 and the DSData Server to connect to an ECOM over the Internet. While we donít recommend that you use this connection scheme for control, it can be quite useful for data collection, ladder program updates, etc. If your Internet connection is through a gateway or proxy server, it can still work, you just need to configure the gateway to let the packets get through to the ECOM - this is discussed in Note 3 at the bottom.

To demonstrate how this works, we have setup an H2-ECOM here at Host Engineering you can use to test out the process. Itís in a base with a DL250 CPU and some I/O. Itís IP address is 12.69.41.166. Follow these instructions to build a link and get online with the ECOM.

 

First we need to determine the approximate round trip time for an IP packet from your PC to the ECOM. We can use Ping to get this number as follows:

       Connect to your ISP like you normally would Ė dialup connection, LAN connection, etc.. Open a Command
       Prompt (DOS session). Enter the following on the command line: 

               Ping 12.69.41.166. Observe the average turnaround time. 

       Close the Command Prompt window.  

Next, you need to build a link to the ECOM.

Open the DirectSOFT32 Launch Window

Create a new link
       right click "Comm Links" and choose "Add Link..."

Click the ĎLink Editorí button
       You have to manually build a link because the default timeouts used in the Link Wizard may be too short when
       connecting across the Internet, and since the Link Wizard uses a broadcast to find the ECOMs on the network,
       these broadcast packets will be filtered out by the gateway and/or routers used to connect you to the Internet.

On the PLC tab select the following:
       PLC Family                   Direct LOGIC 205 Series
       PLC Type                      250

On the Port tab select the following:
       Devices                        Ethernet
       Transport                      Winsock
       Transport Protocol         UDP/IP
       Node Address               IP Address
                                          12.69.41.166   *** see note 3 below about connecting through
                                                                   a gateway or proxy server

       Advanced Settings
               Timeout                (Observed turnaround time +10%)

On the Protocol tab select the following:
       Protocols                      ECOM

Click Auto and the Link Editor should beep at you indicating a successful connection.

Enter a name for your link and click Accept.

Go online with the PLC!
       right click the new link and select Run  


If you want to use this scheme for your own ECOMs, there two keys points you must observe to make this happen:

  1. the ECOM must have a static IP address that is unique on the Internet - that is, an IP address that has been assigned to you by an ISP.

  2. the ECOM must reside outside any firewall or proxy server, these devices typically perform 'IP translation' that will prevent the ECOMs static IP address from being visible over the internet

  3. if you must go through a gateway or proxy server to connect to the ECOM, then you'll need to get the administrator of the gateway or proxy server to create a "hole" through the gateway to the ECOM. This "hole" is a mapping from an IP on one side of the gateway to an IP address on the other side, sometimes using a specific port number.

    In our example, our internal network is using the 192.168.xxx.xxx addressing range and the ECOM is using 12.69.41.166. So we create a UDP/IP mapping, using the above addresses, specifying port 7070 (hex). So
    whenever our gateway gets a packet bound for port 7070, it routes it to the ECOM at 12.69.41.166.

    We cannot give you specific steps to accomplish this because every gateway/proxy server solution will have
    different configuration steps. You just need to tell your IT person to configure it for you, they should know how
    to do this for their specific hardware/software.