What is a node?
In computer networking, a node is any physical or virtual device that is part of a network. This includes hosts like HMIs and PLCs, as well as devices that help manage network traffic, such as routers, switches, and access points.
What is a host?
A host is any device that connects to a network and can send or receive data. This includes computers, servers, PLCs, HMIs, smartphones, tablets, printers, and much more
What is Class of Service (CoS)?
Class of Service (CoS) is a networking feature that prioritizes data traffic to improve performance and reduce latency. CoS is defined by the IEEE 802.1p standard, which assigns priority levels to network packets and is commonly used in industrial automation, VoIP, and video streaming, where certain data needs higher priority. CoS helps ensure critical traffic, like SCADA commands, is delivered without delays. CoS is implemented at Layer 2 using VLAN tagging to classify and prioritize network traffic.
Example Scenario: Real-Time SCADA Communication with CoS:
In a SCADA system, an HMI sends real-time control commands to a PLC over a managed switch. Without CoS, critical control packets may compete with regular network traffic, causing delays. CoS assigns higher priority to control data, ensuring immediate delivery even during network congestion preventing communication delays between the HMI and PLC, maintaining real-time system responsiveness. As a result, industrial processes run smoothly without interruptions or unsafe conditions.
What is a Jumbo Frame?
Jumbo Frame is an Ethernet frame with a Maximum Transmission Unit (MTU) larger than the standard 1500-byte size, typically supporting 9000 bytes or more. This larger MTU reduces the overhead for data transmission, improving network efficiency. Jumbo Frames are often used in high-performance networks to increase throughput, reduce CPU load, and optimize large data transfers.…
What is the Default IP address of a Maple Systems PLC?
To find the default IP address of a Maple Systems PLC, locate the Parameter folder in your project folder in MapleLogic, click the Ethernet tab and you’ll see the default IP address right on top.
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How do I disable the WAN capabilities of an HMI or cMT?
To disable internet access over the HMI’s ethernet port, set the gateway and DNS addresses of the WAN port you want to disable to 0.0.0.0 in the system settings for your device under the Ethernet port Network settings:
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What is Bridge Mode?
Bridge Mode allows a device to function as a network switch, forwarding traffic between LAN ports without modifying packet data. This creates a seamless connection between devices, enabling communication as if they were on the same network. All LAN ports operate as a single network segment, relaying traffic without performing NAT. This mode is useful for extending networks, reducing bottlenecks, and maintaining transparent data flow. Proper configuration of Bridge Mode helps prevent unintended network issues and security risks.
Can I have my LAN ports configured to different networks?
Yes! You can have each LAN port on a cMT or HMI configured for a different network or subnet, in fact, we recommend doing so to keep the ports from conflicting.
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What’s the difference between the two LAN ports on my HMI/cMT?
The specifics will likely differ based on which device you’re specifically working with, but in general, LAN 1 is the port you’d use for a network connection that goes out to the internet, where LAN 2 is strictly for Local Access Networks. In general, we recommend keeping to LAN 2 on your device, unless you…
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Can I overlay objects on a video stream from an IP or USB web camera?
No, because the video input is constantly being updated it is not possible to overlay HMI objects on to of a video stream from an IP or USB camera.
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What is Log4j Vulnerability?
“Maple Systems HMIs are not affected by CVE-2021-44228, also known as Log4shell, and related vulnerabilities including CVE-2021-45046 and CVE-2021-45105. Users of Maple Systems HMIs do not have to take any further action.”
Background
Disclosed on December 9, 2021, CVE-2021-44228 is an Apache Log4j vulnerability which may allow remote code execution (RCE) on the target system by an attacker. Apache Log4j is a universally used logging system for Java-based web and server applications, and due to its widespread usage, many systems and applications may be affected by this vulnerability.
How to find the IP address of an HMI+PLC on a network
HMI+PLC (HMC) To view the programmed Ethernet parameters of your HMC2, HMC3 or HMC7 on the network, press and hold the lower right corner of the screen while powering on. On a HMC4 series screen, press/click and hold the top left corner of the screen for 5 seconds while the device is powered on.
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