Overview

This guide details how to securely access downstream devices, such as PLCs or Cameras, connected to a Robustel router (e.g., R1510, EG5120) from a remote location. By leveraging the Robustel Cloud Manager Service (RCMS) and its RobustVPN feature, users can create a secure VPN tunnel directly to their field equipment. This allows for remote management, programming, and diagnostics as if the user were on the same local network, without needing a public IP address at the remote site. Please note that using the RobustVPN (RVPN) feature requires an RCMS 'Advanced' license or higher.

What You'll Need

Hardware List:

• 1 x Robustel Gateway (e.g., R2010)
• 1 x Downstream Device (e.g., PLC, HMI, IP Camera)
• 1 x PC/Laptop for remote access
• Necessary Ethernet cables

Software & Services:

• An active Robustel RCMS account.
• RCMS License: Advanced or higher.
• The RobustVPN_Manager client application (obtainable from the RCMS Cloud Resource support).

Prerequisites:

• The Robustel gateway must be successfully registered to your RCMS account and show an "Online" status.
• The gateway must have a working internet connection.
• The downstream device's IP address must be in the same subnet as the gateway's LAN IP address.

• Example: Gateway LAN IP: 192.168.0.1 | PLC IP: 192.168.0.10.

Step-by-Step Configuration Guide

Step 1: Create and Configure a VPN Group in RCMS

1. Log into RCMS:

• Open a web browser and navigate to your RCMS cloud instance (e.g., https://rcms-cloud.robustel.net).
• Log in with your user credentials.
  
  

2. Navigate to VPN Group Management:

• From the left-hand menu, select RVPN -> VPN Group Management.
  
  

3. Create a New VPN Group:

• Click the Create VPN Group button.
• Set the Group Type to Virtual IP only.
• Enter a descriptive name for the group (e.g., PLCAccessGroup).
• Click OK.
  
  

4. Assign Devices and Users:

• Once the group is created, click its name to manage it.
• In the Device tab, click Assign to add the target Robustel gateway to this group.
• In the User tab, click Assign to add the user account(s) that will be granted remote access.
• After assigning, confirm that the VPN Group Status and Server Status both show as "Normal".
  
  

• In the “Virtual IP only” group, you need to add the PLC’s IP address on the “End Device Maintenance” page of the RCMS platform and enable initialization.
  After initialization, the VPN user can directly ping or access the PLC using professional software (such as TIA Portal) for remote debugging.
  
  

Step 2: Enable RobustVPN Function on the Gateway

Note: In many cases, this can be configured remotely via RCMS, but local access is also an option.

1. Log into the Gateway's Web Interface:

• Access the gateway's configuration page using its LAN IP address (default: http://192.168.0.1).

2. Configure RCMS and VPN Settings:

• Navigate to Services -> RCMS.
• Ensure the RCMS service is enabled (Enable is set to ON).
• Under the RobustVPN section, check the box to Enable the VPN function.
• Click Submit then Save&Apply to save the changes.
  
  
  

Step 3: Connect and Access the Downstream Device

1. Install the VPN Client:

• Install the RobustVPN_Manager client application on the PC you will use for remote access.
  
  

2. Log in and Start the Connection:

• Open the RobustVPN Manager client.
• Log in using the same user credentials that you assigned to the VPN group in Step 1.
  
  
• From the dropdown list, select the VPN group you created (e.g., testVPNGroup).
• Click the Start Connection button.
  
  

3. Access the Downstream Device:

• Once the VPN status shows "Connected," your PC has successfully joined the virtual network.
• You can now access your downstream device directly using its IP address. For example, open your PLC programming software and connect to 192.168.0.10, or type http://192.168.0.10 into a web browser to access its web interface.

Verification & Testing

To confirm a successful connection:

1. Check Client Status: The RobustVPN Manager client should clearly display a "Connected" status and show a virtual IP address has been assigned to your PC.
2. Ping the Device: Open a Command Prompt or Terminal on your PC and ping the IP address of the downstream device (e.g., ping 192.168.0.10). A successful reply indicates that the network tunnel is working correctly.

Pinging 192.168.0.10 with 32 bytes of data:
Reply from 192.168.0.10: bytes=32 time=58ms TTL=64
Reply from 192.168.0.10: bytes=32 time=57ms TTL=64

Troubleshooting / FAQ

• Q1: I cannot connect with the RobustVPN client. What should I check?
  A1:

1. Verify your user account has been correctly assigned to the VPN group in RCMS.
2. Ensure the target gateway is online in RCMS and shows its VPN status as "Connected."
3. Check that the gateway has the latest version of the RobustVPN app installed (viewable in RCMS under Apps).
4. Confirm your PC's firewall or antivirus is not blocking the VPN client.

• Q2: The VPN is connected, but I still can't access my PLC/HMI.
  A2:

1. Double-check that the PLC's IP address is in the same subnet as the router's LAN IP.
2. Ensure the PLC's gateway address is set to the router's LAN IP (e.g., 192.168.0.1).
3. Verify that the PLC's own firewall (if it has one) is not blocking access from the virtual IP range.
4. Use the "Diagnostics" feature in RCMS to run CLI commands on the router (like ping 192.168.0.10) to confirm the router itself can reach the device.

• Q3: Is the remote connection secure?
  A3: Yes. RobustVPN creates an encrypted tunnel between your PC and the remote gateway. For added security, RCMS allows you to create temporary access links (for protocols like HTTPS/RDP) that can be set to expire after a maximum of 99 hours. Always monitor the "Activity Log" in RCMS to audit access records.

Revision History