What products are involved?

Rheonics SRV viscometer, SRD density-viscosity meter, DVP gas density-viscosity meter and DVM HPHT density-viscosity meter

What is the purpose of this article?

This article provides guidance on diagnosing and resolving firewall-related communication issues between the Rheonics Control Panel (RCP) software and sensor electronics when using Ethernet Connection option.

Table Of Contents

• 1. Overview
• 2. Identifying Blocked Ports
  • 2.1 Port 21 Blocked (FTP Issue)
  • 2.2 Port 10001 Blocked (No Sensor Connection)
• 3. Resolving Firewall Issues
  • 3.1 Network Firewall: Working with IT to open the ports
  • 3.2 Local PC Firewall: Windows Defender Firewall
  • 3.3. TCP Port Configuration (Alternative Solution)

1. Overview

Rheonics Control Panel (RCP) is Rheonics' software that allows users to fully utilize the potential of Rheonics' inline viscometers. RCP is used for sensor configuration, reading and trend visualization, log files extraction, and more.

When using Ethernet connection, firewall restrictions can block communication between the Rheonics Control Panel (RCP) software and sensor electronics, making it difficult to monitor and manage devices. These issues typically occur at two levels:

1. Network-Level Firewall Issue: This occurs when a firewall exists between the user’s LAN, where the RCP is installed, and the factory LAN, where the sensor is connected, blocking communication.
2. Local PC Firewall Issue: When the Windows Defender Firewall on the user's PC blocks RCP communication.

Figure 1. Company Network Diagram. Firewall between RCP and Factory LAN

Figure 1 illustrates a typical setup, within a company network. where RCP runs on a user’s PC, and the sensor electronics are connected on a different LAN. A firewall in between these networks, blocking the ports that the RCP needs, can interrupt communication.

RCP primarily uses two network ports:

• Port 21 (TCP): FTP for downloading sensor logs, on RCP Logger Tab when connected via Ethernet.
• Port 10001 (TCP): Required for direct sensor communication when connected via Ethernet.

RCP can be used by connecting to Rheonics Viscometer in two ways: USB and Ethernet Connection. To learn more about RCP and how to use it, refer to Rheonics Support Portal - RCP.

Firewall issues occur only when connecting via Ethernet or when a firewall rule blocks RCP ports.

2. Identifying Blocked Ports

2.1 Port 21 Blocked (FTP Issue)

If Port 21 is blocked, attempting to download sensor logs, on the Logger Tab of RCP, will result in an error message stating, "The file transfer was not successful". Notice how after clicking the Refresh button, the software failed to pull the logs (Figure 2)

Figure 2. RCP - TCP 21 Port Blocked.

2.2 Port 10001 Blocked (No Sensor Connection)

If Port 10001 is blocked, RCP will fail to establish a connection, and the status indicator will remain red, signaling that there is no communication with the sensor.

Figure 3. RCP - No Connection, TCP 10001 Blocked

A clear indication of blocked ports is when RCP connection works via USB, allowing sensor log downloads, but LAN-based communication fails.

3. Resolving Firewall Issues

3.1 Network Firewall: Working with IT to open the ports

If there is a firewall rule blocking communication between RCP and the viscometer:

1. Contact IT and request a firewall rule allowing inbound and outbound traffic for:
   • Port 21 (TCP) for FTP access.
   • Port 10001 (TCP) for sensor communication.
2. The firewall rule should allow communication between the sensor’s IP address and the user’s PC where RCP is running.

3.2 Local PC Firewall: Windows Defender Firewall

There are steps that can be taken, if the user has the permissions, to allow traffic through the firewall. Security measures and firewalls vary by company; the steps below use Windows Defender Firewall as an example.

3.2.1 Allowing RCP in Windows Defender Firewall

Windows Defender Firewall could be blocking communication with Rheonics viscometer.

If you have the necessary permissions: 

1. Open Windows Defender Firewall.
2. Navigate to Allow an app or feature through Windows Defender Firewall.
3. Find Rheonics Control Panel and ensure it is allowed.
4. If RCP is not listed, add it manually and allow it through.
   
   

Figure 4. Allow RCP in Windows Firewall

3.2.2 Checking and Modifying Firewall Rules

If you have the necessary permissions:

1. Verify that Ports 21 and 10001 are open for inbound and outbound traffic in Windows Defender Firewall.
2. If a rule is blocking port 10001, consider deleting it or making it more granular:
   • Restrict it to specific programs instead of blocking all traffic.
   • Specify which IP addresses should be blocked.

Figure 5. Rule blocking port 10001

3.2.3 Work with IT for a Firewall Rule

In some cases, a lack of authorization may prevent a user from making changes to Windows Defender Firewall. In such cases, users should contact their IT team to request a firewall rule allowing inbound and outbound traffic for Ports 21 and 10001 (TCP).

3.3. TCP Port Configuration (Alternative Solution)

If Port 10001 is unavailable due to network constraints, it can be modified by Rheonics Support. For example, the terminal port can be changed to 10002, allowing communication through a different port (Figure 6)

Figure 6. RCP Communication through TCP Port 10002

Contact Rheonics Support for TCP Port 10001 Configuration.