To use RDE300 Series Engineering Client Software with an RDE300 series unit that is on a local network accessed via a cellular modem, observe the following.

Set Up Port Forwarding On Your Cell Modem.

Give your RDE300 series unit an IP address on the local network that is accessed via the cell modem. The modem itself will have another IP address, determined by the cellular service provider.

You must configure the cell modem to forward communication from RDE300 Series Engineering Client Software to the RDE300 unit.

On your modem's port forwarding configuration page, set up the following:

Public Start PortPublic End PortProtocolHost IPPrivate Start Port
502502TCPRDE300 local IP502
502503UDPRDE300 local IP502
6969TCP & UDPRDE300 local IP69

Disable DMZ Host

If your modem supports DMZ Host, this should be disabled.

Disable Dynamic DNS

Disable dynamic DNS on your modem to ensure that the modem will communicate with the RDE300 at its static local IP address entered in the port forwarding table above. 

Use the Latest Version of RDE300 Series Engineering Client

Make sure you are using the latest version of RDE300 Series Engineering Client Software. Earlier versions may not work properly for communication via cell modem. See RDE300 Series Engineering Client Software Release Notes.

Use the Modem's IP Address in RDE300 Engineering Client

Launch the RDE300 Engineering Client Software. Enter the modem's IP address in the address field for connecting to the RDE300. Since port forwarding is set up, the modem will forward the software's communications on ports 502, 503, and 69 to the RDE300 unit.


Port 502 is used for Modbus TCP communication, which is used by RDE300 Engineering Client Software for communication with the RDE300. When using port forwarding as described above, you may not have any other Modbus TCP devices on the local network that is accessed by the cell modem.


We strongly advise configuring and testing the above setup in an office environment before deploying the equipment to the field, in order to make sure that any settings issues can be resolved easily. Incorrect settings, including possibly other modem settings not listed above, could result in inability to communicate with the RDE300 remotely.