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What is required for for me to be able to connect to the PLC from the internet/outside the company network?

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Netgear DG834V3


Hello there!


After the trials and tribulations of learning ladder logic to an acceptable degree, I have embarked on a journey into networking! 

What I aim to do, is to be able to use remote operator from any location with a internet connection. There didn't appear to be a webinar addressing this issue.


The PLC is connected to a modem within a network

My ethernet connection appears to be valid as i can ping the PLC from another computer on the network. I have forwarded port 20256 in the router config.

So i gather that that means that I can access the PLC using Remote Operator as long as I'm within the company's network..


So my question is: What is required for for me to be able to connect to the PLC from the internet/outside the company network?


Please let me know if there is any more information that you require


I have attached my current ladder logic, please feel free to edit.


Thanks in advance






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Check if the router is compatible with dynamic dns providers.  The you can access the router from the internet using a domain name.  Google should tell you all you need to know in setting this up.  Then it is as simple as forwarding port 20256 to your PLC in the router.

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The company's router has a static IP which I've now located and entered the default gateway into the Card INIT FB


I can now connect to the PLC through the company's LAN and sporadically through the internet.


When i click 'Get OPLC iNFORMATION' (from outside the company's network), it retrieves the relevant info. That tells me that my logic at least can connect to the PLC.


However, the connection doesn't seem to be stable, as two minutes after I've got the plc information, i get error message 210. (The usual Comm Error message). Thus, i cannot read any changing operand values, or use Remote Operator.


Always found these forums to be most helpful! Learning networking and PLC programming all in one go!

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