LS300 UDP or TCP to Serial

I am trying to connect a LS300 using its serial port to a WANCO Message sign. I can talk to the sign hardware through WANCO proprietary software using the signs serial connection directly and Null Modem Cable and my communication is good. I have also tried using WANCO software and a Pinpoint X under Verizon Wireless using standard cable and communication is good. When I connect the LS300 and setup using same parameters as we used on PinpointX the WANCO software times out at 21 seconds which I believe is the setting for UDP. I have no problem communicating to the Modem, nor directly to the sign. The modem acts as if it cannot pass traffic across it to the serial port. Do I need to set up port forwarding somehow to communicate directly to serial for this model?

Checked to see in the Serial tab that UDP auto answer is enabled and check what the Startup Mode Default is. If you are just polling the device behind the LS300 “Normal (AT command” would work. If that does not work try UDP as the startup mode.

Also click in the Status --> Serial section. When you try to hit the serial device the Serial Bytes sent and received should increase.