Introduction to Hubs

Thank you for purchasing the Hubport, a self-powered Universal Serial Bus (USB) hub designed to provide a convenient and effective means of bringing USB connectivity to your PC, server, or laptop. The Hubport also delivers the potential of Digi International’s Edgeport USB to Serial (RS-232) expansion module.

Hubs, critical components in the USB architecture, are wiring concentrators that enable the attachment of multiple devices, thus converting a single attachment point into multiple attachment points. USB architecture allows a cascaded multiple hub configuration with certain power limitations (explained later in this section). See figure 1.

PC Host

	Hub po rt
Edgeport	Edge po rt		Hubport
	Edge port	bu s-powered hub		scanner
		j oystick	mouse

Figure 1: Example of a Typic al Hub Configuration

Each hub has an upstream port, connecting to the host, and multiple downstream ports, connecting to downstream devices, possibly including other hubs. A hub can detect attachment and detachment of downstream devices and enable and monitor the distribution of the power to downstream devices via their integral hardware and the operating system.

Each USB device reports its power requirements to the operating system, which then enables and disables the device as a function of its power requirements and the amount of available power. High powered devices typically need to be connected to a self-powered hub, such as the Hubport, which obtains power from its external power supply and provides up to 500 mA for each downstream port. Only low powered devices, such as a mouse, can be connected to a bus-powered hub, which obtains power from its upstream host and provides up to 100 mA for each downstream port.

Due to the limited available power for bus-powered hubs, cascading two bus-powered hubs is an illegal topology, and devices connected to the second hub will not function. USB specifications limit the connection of a bus-powered hub to a self-powered hub or host only. All Hubports, except the Hubport/4c in bus-powered mode, operate as self- powered hubs, and are not affected by this limitation.

According to the USB Specification, the maximum limit of hubs cascaded in series cannot exceed five. In other words, you may have a maximum of five hubs between any device and the host. This does NOT mean that the maximum number of hubs in a system is five. Indeed, up to seven hubs can be connected parallel at any given level. You must tally both external and embedded hubs when counting downstream hubs.

Hubport Installation Guide (90000664 Rev. B) – Page 1

Hubport/7c DC, Hubport/7c, Hubport/4, Hubport/4c DC, Hubport/4c specifications

Digi Hubport series, including models such as Hubport/4c DC, Hubport/7, Hubport/4c, and Hubport/7c is a groundbreaking family of modular connectivity solutions designed for demanding industrial and commercial environments. These devices are engineered to enhance data transmission and connectivity, catering specifically to applications that require high reliability and performance.

One of the standout features of the Digi Hubport models is their ability to support multiple devices simultaneously through a single connection. Hubport/4c DC, for instance, can seamlessly connect four devices, while Hubport/7 and Hubport/7c offer connections for seven devices. This modular approach allows for greater flexibility and scalability in network design, accommodating various device types and configurations without needing additional infrastructure.

In terms of technology, the Hubport series employs advanced USB technology for high-speed data transfer, ensuring that all connected devices operate efficiently and effectively. The integration of USB 3.0 in models like Hubport/7c enhances the data transfer rates, making it particularly suitable for environments requiring rapid data access and processing, such as data centers and manufacturing facilities.

The Hubport series also boasts enhanced power management capabilities. Model Hubport/4c DC features dual power supply options, ensuring uninterrupted operation even during power fluctuations. This characteristic is crucial for industrial applications where downtime can result in significant financial losses.

Another notable aspect of the Digi Hubport series is its rugged design. Built to withstand harsh environmental conditions, these hubs are often equipped with protective enclosures that ensure durability and longevity. This resilience makes them ideal for use in factories, warehouses, and outdoor settings where traditional electronics may fail.

Additionally, the Digi Hubport devices support plug-and-play functionality, simplifying installation and reducing the time required to set up new systems. Users can easily connect devices without the need for extensive technical knowledge or complex installation processes.

Security is also a critical consideration in the Digi Hubport design. These devices include features that protect against unauthorized access and data breaches, ensuring that sensitive information remains secure throughout its transmission and processing.

In summary, the Digi Hubport series, encompassing Hubport/4c DC, Hubport/7, Hubport/4c, and Hubport/7c, provides a robust and flexible connectivity solution tailored to meet the needs of diverse environments. With high-speed data transfer, modular connectivity, rugged durability, and comprehensive security features, these devices are set to revolutionize the way industries approach connectivity and data management.