H685 User Manual
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4.17 Serial DTU point-to-point solution not working
Problem: Take two H685. Both support Serial to cellular gateway feature (DTU feature). Configure one as client,
the other as server. But no work.
Answer: First, we confirm that the H685 both are online, and the server’s IP is public IP that can be ping through
from other networks.
Second, we confirm both H685’s DTU feature (Serial to Cellular Feature) are working. We test an example as
follows,
H685 DTU with vodafone SIM as client (in Germany)--- China Telecom as server (In China): working
H685 DTU with vodafone SIM as server (in Germany)--- China Telecom as client (In China): working
H685 DTU with vodafone SIM as client (in Germany)---- H685 DTU with Vodafone SIM as server (in
Germany) : no working
This indicates the two Vodafone SIM cards cannot communicates each other. The Vodafone ISP limit the two
internal’s SIM card’s communication.
You have two ways to solve the problem.
1) Get another SIM card from another ISP to test.
2) Ask the Vodafone ISP to unlimit two Vadafone SIM's communication.
4.18 Can’t open device /dev/ttyUSBx.
Problem: Status page shows “Can’t open device /dev/ttyUSBx”.
Solution:
Step 1) H685 Router Web – Internet Settings – WAN, at Cell Modem, please choose “AUTO_DETECT” and click
“Apply” button.
