USB to Serial Adapter Wiki

USB to Serial adapter Wiki by Magneto Tech Research

USB to Serial adapters

What is a USB to Serial adapter and how is it used? How do I choose the right model and how do I connect it? What to look for when shopping for a USB to Serial adapter. Here are answers to all your basic (and possible advanced) USB to Serial questions in an easily understandable language.

What is a USB to Serial adapter?

The USB to Serial adapter, a type of USB adapter, comes in many models, sizes, and shapes, here are a few examples:

 

What are the differences between USB to Serial adapters?

So what is the main differences between these USB to serial adapters? These adapters enable serial port connections, allowing legacy devices to connect through USB interfaces. Multi-port adapters, often referred to as a serial adapter hub, are designed to expand serial connectivity through a single USB interface. The most obvious difference is the physical size of the adapters; this is mostly due to the number of ports the particular adapter has. For example a one port adapter is much smaller than a four port adapter. However mostly the physical size of the USB to serial adapter is actually the least important feature, more importantly are the electrical features of the adapter. More about that later. Other differences are that some adapters has a female DB9 port instead of a male DB9 serial port. Some have thumb screws for attaching the DB9 connector to a device while others have screw nuts for connecting devices. Most USB to Serial adapters has a DB9 connector however some adapters has a screw terminal header instead, this applies to industrial adapters and converters in particular. One of our favorite features of the USB to serial adapter is the type of adapter which have indication lights for the TX and RX communication lines. This is a very helpful feature when troubleshooting. Okay, but how about the inside of the adapter? Well, the circuitry inside the adapter is even more important that the outside. The main parts of the inside circuitry consists of two processor chips: a USB to Serial processor chip, this chip converts all the USB data to serial data and all the serial data to USB data, and a Serial driver chip, this chip provides the power for your the device connected to the serial port of the adapter; it kind of amplifies the signals. We highly recommend a USB to serial adapter designed with a well known brand of USB processor and driver chip. Examples of well known brands are FTDI and Silicon Labs. The seller of the adapter should be able to tell you which processor brand is inside the chip, if they cant tell you, don’t buy it. The problem with an unknown or low-cost processor and driver ship is that it will most likely cause you more problems when installing the drivers or when trying to communicate with your serial device. The reason is that low-cost processor chips are often poorly designed and have incompatible drivers.

Interface types.

USB to Serial adapters comes in several different variations in regards to interface types. The most commonly used interface type is serial RS232. Other frequently used interfaces are RS485 and RS422. Regardless of which interface type the adapter has it usually looks the same, with the one difference that RS232 adapters usually have a DB9 connector for connecting to the serial device where as the RS485 and RS422 adapters usually have a screw terminal header for connecting a serial device. We will not go into the details of how the RS232, RS485 or RS422 protocol works, but if you are interested in this then there are lots of RS232, RS485 and RS422 information on Wikipedia.

How to use a USB to Serial adapter.

Before you can start using a you need to install the drivers for the adapter. These drivers facilitate serial port connections, enabling legacy devices to communicate through USB interfaces. The drivers are small files / programs which makes it possible for your computer to find the adapter and help in converting the data sent and received from your serial device. Usually drivers are available for Windows, Linux and Mac operating systems, however some low-cost adapters only have drivers for Windows, which is another reason for selecting a quality USB to Serial adapter. Installing the drivers are easy if you have a good USB to serial adapter, usually you can install the drivers simply by starting an exe file and the drivers will automatically installed. However, some of the higher level high quality adapters offers an option to install the driver files manually, this can be an advantage it you want to control exactly what is installed. After the drivers has been successfully installed, you will be able to find the new virtually created serial COM port in your operating system’s Device Manager where different parameters for the COM port, such as baud rate and data bits, can be configured. A standard RS232 USB to serial converter with a DB9 connector is usually very easy to connect to a serial device, simply connect the DB9 connector to the serial device, the DB9 connectors needs to be female / male to be able to connect, and it is an advantage if one of the connectors has thumb screws and the other has nuts.

Serial Port Connection Examples.

1-port RS232 interface

Let’s take a look at one of the most simple setups using a USB to serial adapter with RS232 interface:

This setup enables serial port connections, allowing legacy devices to interface with modern computers through USB.

In this setup, a serial cable is used to connect the USB to serial adapter to the serial device. This setup simply connects one computer with a serial device by a 1-port USB to serial adapter. It is recommended to keep the USB cable less than 5 feet to maintain reliable data transfers.

Multiport RS232 interface

Below is a typical setup of a 4-port USB to serial converter with RS232 interface:

This configuration expands serial port connections, facilitating the integration of multiple legacy devices through a single USB interface.

With this setup, there are four virtual COM ports visible in Device Manager within the computer’s operating system. The COM port number can be individually changed and several parameters for each COM port can be configured.

RS485 interface

As mentioned earlier, the USB to RS485 converter with an RS485 or RS422 interface usually has a screw terminal header instead of a DB9 connector for connecting the communication wires. This setup supports serial port connections, enabling long-distance communication between legacy devices and modern systems. Below is an example of a setup using RS485. One of the advantages of using an RS485 connection is that the communication wires can be up to 4000 feet long. For this reason, RS485 is often used to extend data signals whereas RS232 is usually only used as a converter between two types of data signals.

Port-powered and externally powered adapters.

In regards to powering the USB to Serial adapter, there are two ways of doing this. Usually, a single port USB to serial adapter is powered by a single USB port, even many four-port converters are powered by the USB port. This is the most convenient way because it does not require any additional power cables. However, most adapters with more than four serial ports are powered by an external power supply. The reason is that a standard USB port does not have sufficient power to provide power for multi-port adapters. Also, most isolated industrial grade adapter is using an external power supply due to its isolation requirements.

Optical isolated adapters.

Some USB to Serial adapters can be either non-isolated or isolated. An isolated USB to Serial adapter typically connects to the computer via a USB-A port, providing additional protection and reliability. An isolated USB to Serial adapter have optocouplers and TVS (Transient Voltage Suppressors) separating the data lines inside the unit to prevent high voltage spikes, surges, ground-loops and noise from damaging and interfering with your computer or the device you have connected to the serial port. Some USB to Serial adapters even have the external power supply isolated from the rest of the adapter, this provides additional protection and reliability. Usually isolated adapters and converters are used only if the user wants to additionally protect the device or equipment connected to the network (in case the equipment is of high value), or if there are reasons to suspect high voltage spikes or similar in the network. A non-isolated converter usually only has high-speed surge suppressor at each communication line as a simple protection against static electricity and low-voltage spikes which is sufficient for general use.

Applications of USB Serial Adapters

USB serial adapters have a wide range of applications across various industries, making them indispensable tools for modern computing environments. These adapters facilitate serial port connections, enabling legacy devices to interface with modern computers. These adapters are particularly useful for connecting legacy serial devices to contemporary computers that lack built-in serial ports. Here are some common applications:

• Connecting Serial Peripherals: USB serial adapters are frequently used to connect bar code scanners, printers, and other serial peripherals to modern computers. This ensures that businesses can continue using their existing equipment without needing to upgrade to newer models.

• Industrial Control Systems: In industrial settings, USB serial adapters enable legacy serial connections for control systems, medical devices, and other specialized equipment. This is crucial for maintaining the functionality of critical systems without extensive overhauls.

• Handheld Devices: Many GPS devices, PDAs, and other handheld devices rely on serial communication. USB serial adapters provide a reliable interface for these devices, ensuring seamless data transfer and connectivity.

• Scientific Instruments: Data acquisition systems, laboratory equipment, and other scientific instruments often use serial communication. USB serial adapters facilitate these connections, allowing researchers to collect and analyze data efficiently.

• Retail Applications: Point-of-sale systems, kiosks, and other retail applications benefit from USB serial adapters by enabling serial connections for various devices, ensuring smooth and uninterrupted operations.

By bridging the gap between old and new technologies, USB serial adapters play a vital role in maintaining the functionality and efficiency of numerous systems and devices.

How to choose the right USB to Serial adapter.

When shopping for a USB to RS232 serial adapter you should first determine if you need an industrial strength or a commercial/consumer grade adapter, this depends on in what kind of environment you plan to use the adapter. Next you should determine if you need an isolated or non-isolated adapter, and then you can decide if you need an externally powered adapter or if you can use a port-powered adapter. Usually a port-powered adapter will suffice for most general applications. Finally you should decide if you want LED lights for the TX/RX lines, this can be very helpful when troubleshooting and is highly recommended for ensuring compatibility with your existing USB port.

• The check list looks like this:

• Determine if you need an industrial or consumer grade adapter.

• Determine if you need an isolated or non-isolated adapter.

• Determine if you need a port powered or externally powered adapter.

• Decide the connector type (DB9 or screw terminals).

• Optional LED lights for communication activity.

Troubleshooting and Compatibility Issues

When using a USB serial adapter, users may occasionally encounter compatibility issues or errors. Here are some common troubleshooting tips to help resolve these problems:

• Proper Installation and Configuration: Ensure that the USB serial adapter is correctly installed and configured on your computer. This includes verifying that the adapter is securely connected to both the computer and the serial device.

• Driver Verification: Check that the correct drivers are installed for both the USB serial adapter and the serial device. Incompatible or outdated drivers can cause communication issues.

• Connection Check: Make sure the serial device is properly connected to the adapter. Loose or faulty connections can lead to data transfer problems.

• Conflict Resolution: Look for conflicts with other USB devices or serial ports on your computer. Disconnecting other devices or changing port assignments may resolve these conflicts.

• Manufacturer Support: Consult the user manual or the manufacturer’s website for specific troubleshooting guides and FAQs. Many manufacturers provide detailed instructions and support resources to help resolve common issues.

By following these troubleshooting steps, users can address most compatibility issues and ensure a smooth connection between their serial devices and modern computers.

USB Serial Adapters vs. Traditional Serial Ports

USB serial adapters offer several advantages over traditional serial ports, making them a preferred choice for many users:

• Convenience: USB serial adapters are easy to install and use, eliminating the need for IRQ, DMA, or I/O port resources. This simplifies the setup process and reduces potential conflicts.

• Flexibility: These adapters can be used with a wide range of serial devices and operating systems, providing a versatile solution for various applications.

• Reliability: USB serial adapters provide a reliable connection, with fewer errors and less data loss compared to traditional serial ports. This ensures consistent performance and data integrity.

• Compatibility: Modern computers often lack built-in serial ports. USB serial adapters bridge this gap, allowing users to connect serial devices to existing USB ports without needing additional hardware. USB serial adapters enable serial port connections, bridging the gap between legacy devices and modern computers.

• Cost-effectiveness: USB serial adapters are often less expensive than traditional serial ports. They also allow users to continue using their existing serial devices, avoiding the cost of upgrading to newer equipment.

Overall, USB serial adapters offer a practical and efficient solution for connecting serial devices to modern computers, providing numerous benefits over traditional serial ports.

Security Considerations for USB to Serial Adapters

In today’s interconnected world, security is paramount, even when using USB to serial adapters. Here are some key security considerations to keep in mind:

• Physical Security: Don’t overlook the physical security of your USB to serial adapter and connected devices. Secure them in a safe location to prevent tampering or theft, which could compromise your data.

• Genuine processor chips: make sure the components inside the adapter are genuine to prevent problems with counterfeit components.

• Regular Updates: Keep your adapter’s firmware and drivers up to date. Manufacturers often release updates that include security patches and new features, helping to protect your devices from emerging threats.

• Compatibility: Ensure that your adapter is compatible with your operating system and devices. Incompatible adapters can introduce security vulnerabilities, making your system more susceptible to attacks.

By considering these security factors, you can minimize the risks associated with using USB to serial adapters and ensure a secure connection between your devices.

Environmental Impact and Sustainability of USB to Serial Adapters

As we become more conscious of our environmental footprint, it’s important to consider the sustainability of the technology we use, including USB to serial adapters. Here are some key factors to consider:

• Energy Efficiency: Opt for USB to serial adapters that boast low power consumption. Energy-efficient adapters not only reduce your electricity usage but also help minimize your carbon footprint.

• Recyclable Materials: Choose adapters made from recyclable materials. This choice supports sustainable manufacturing practices and helps reduce electronic waste, contributing to a healthier planet.

• Compact Design: Adapters with a compact design are not only convenient but also environmentally friendly. Smaller adapters require less packaging, which reduces waste and lowers transportation emissions.

• Long-Lasting: Invest in high-quality adapters with a long lifespan. Durable products reduce the need for frequent replacements, thereby minimizing electronic waste and conserving resources.

• Responsible Manufacturing: Support manufacturers committed to environmentally responsible practices. Look for companies that prioritize sustainability in their production processes and have a strong commitment to reducing their environmental impact.

• End-of-Life Recycling: Ensure that your adapter can be recycled at the end of its life cycle. Proper recycling helps recover valuable materials and reduces the amount of waste sent to landfills, promoting a circular economy.

By considering these environmental factors, you can make a more sustainable choice when selecting a USB to serial adapter and contribute to a more environmentally friendly future.

Detailed specifications for other USB to serial adapters:

The Mini USB to Serial adapter
The Standard USB to Serial adapter
The PRO USB to Serial adapter

Conclusion

USB serial adapters are a versatile and reliable solution for connecting legacy serial devices to modern computers. With their wide range of applications, ease of use, and compatibility with various operating systems, USB serial adapters are an essential tool for many industries. By understanding the applications, troubleshooting tips, and advantages of USB serial adapters, users can ensure a smooth and efficient connection between their serial devices and modern computers. Whether for industrial control systems, scientific instruments, or retail applications, USB serial adapters provide a seamless bridge between old and new technologies, ensuring continued functionality and efficiency.