Key Points
- RS232 and FireWire serial cables are no longer used in laptop or desktop computers, with USB connectors being the primary connection for computer peripheral devices.
- Serial cables are genderless, but the connectors on each end have a gender, with male connectors having nine extruding pins and female connectors having an empty conductor.
- RS232 serial cables have a slow data transfer rate of 1Mbps to 15Mbps and are primarily found in older printers, modems, or time clock applications.
- RS422 and RS485 serial connections have a longer distance range and are commonly used in industrial manufacturing environments for video surveillance, card readers, and security control panels.
- USB-C is becoming the industry standard for serial connections, offering fast data transfer rates and versatile compatibility with various devices.
Serial cables and connectors are used to transfer data between computers or between a computer and peripheral hardware devices. Three primary serial cables and connector categories have been heavily utilized in personal computers: RS232/RS422/RS485, FireWire, or USB connections. However, RS232 and FireWire serial cables have since fallen out of favor and are no longer used in laptop or desktop computers. The USB connector is now the primary connection for computer peripheral devices.
There are many different types of USB connectors and one size does not fit all! Other serial connections have differing physical shapes, pin configurations, data transfer rates, and data transfer methodologies. The wrong connector will leave you with no data transfer between devices.
Serial Cables and Connectors: Let’s Talk About Gender
Serial cables are genderless, but the connectors located on each end of the cable have a gender. Be aware of the serial cable connection variances. It’s easy to order (not that we’ve ever done it!) a serial cable with the wrong connections — a male-to-male when we wanted a male-to-female connection.
Male Connector
The male RS232 connector has nine extruding pins. Male plugs will fit into the female plugs. The male connector is also called the “plug.” The plug has a solid pin that acts as the conductor.
©Albert Lozano/Shutterstock.com
Female Connector
The female connector is often called the “jack.” The center of the connector contains an empty conductor for the male connector.
©The Len/Shutterstock.com
Best for RS232 to USB A: OIKWAN USB-A to RS232
- USB 2.0 to RS232 male DB9
- Supports data transfer speeds up to 1Mbps
- FTDI USB serial with the latest FTDI chipset
- Geared for devices such as GPS, routers, serial modems, barcode scanners, label writers, digital cameras, and card readers
The OIKWAN USB-A to RS232 is our selection for the best USB-A to RS232 connection. The OIKWAN is a 2.0 USB with a serial cable connection of a male DB9.
The RS232 serial cable was developed in the 1960s. The RS232 serial cable was at the height of its popularity in the 1990s. You may still find RS232 serial connectors in older laptops and desktops, but primarily you’ll find an RS232 port in older printers, modems, or time clock applications.
An RS232 serial connection sends one single data bit at a time through the cable. The slow transfer mechanism has made the RS232 obsolete in more current technologies. The standardized pin configuration of the RS232 allowed different product types to communicate back and forth with each other. Today, serial ports with RS232 connectors are obsolete technology. You won’t find RS232 ports on new computers.
A USB to RS232 serial connection allows businesses to breathe new life or extend the life of legacy technology devices. A company with thousands of devices is far more interested in extending the life of an existing device rather than replacing it.
| Pros | Cons |
|---|---|
| Bring old printers back to life! | The RS232 has a very slow data transfer rate of roughly 1Mbps to 15Mbps. |
| There are not very many devices with an RS232 connection. | |
| Locating computer software drivers for legacy devices with an RS232 connection may be very challenging. |
Best for RS232 to USB-C: OIKWAN USB-C to RS232
- USB-C male, RS232 DB9 male
- FTDI-FT232RL chipset
- Plug and play after driver installation
- Great for cash registers, modems, bar code scanners, label printers, digital cameras, and more
The OIKWAN USB-C to RS232 is our selection for the best USB-C to RS232 connection. The OKIWAN allows the current technology node laptops and desktops with USB-C to connect to RS232 devices. The OKIWAN has a male DB9 serial connection (9-pin) and a USB-C (24-pin) connection.
The OIKWAN USB-C allows you to dig through your discarded technology bins in the closet and find out what images are hiding inside that 2005 digital camera relic. The USB-C to RS232 will allow you to connect your digital camera, PDA, label printer, or other elder technology devices.
| Pros | Cons |
|---|---|
| A USB-C is relevant to current laptop and desktop hardware configurations. | Connecting older RS232 devices to a current technology node laptop or desktop is not for the faint of heart. |
| Multiple devices can be connected instead of a single device with an RS232 connection. | You may need new drivers for your legacy hardware and it could take some time to find a functional, generic driver. |
Best for RS422/RS485 to USB: DTech USB to RS422 RS485 Serial
- Connect your RS485 or RS422 device to your computer's USB port
- FTDI FT232 chipset
- Supports Windows versions 7-11, Mac, and more
- Plug-and-play
The DTech USB to RS422 RS485 is our choice for the best USB to RS422/RS485 serial connection. An RS232 connection is distance limited to a maximum of fifty feet. An RS422 or RS485 connection distance may stretch from fifty feet to several kilometers. An RS422 is a full-duplex, and the RS232 and RS485 are half-duplexes.
The DTech USB allows the user to plug into an RS422 or RS485 serial connection with one device instead of carrying separate RS422 and RS485 devices.
You’ll find RS485 connections in industrial manufacturing environments. The twisted paired wiring is excellent for long-distance runs in noisy environments. RS485 is preferred for video surveillance, card readers for site access, and security control panels.
| Pros | Cons |
|---|---|
| You only need one device instead of both RS422 and RS485 devices. | It requires a CD software driver. |
| The converter makes it easy to add RS422 and RS485 serial ports and devices to your current system. |
Let’s take a quick look at the performance characteristics of RS232, RS422, and RS485. While they sound similar and are often confused with each other, they’re pretty different!
Half-Duplex
A perfect example of a half-duplex is a walkie-talkie. The data can only be sent in one direction at a time. One person can send data while another person receives it. The two parties are unable to speak at the same time.
Full-Duplex
A cell phone is an excellent example of a full-duplex. Data can be sent and received simultaneously. Both parties can speak and hear at the same time.
| RS232 | RS422 | |
|---|---|---|
| Transmission Mode | Full Duplex | Half Duplex |
| Transmitters | 1 | 1 |
| Receivers | 1 | 10 |
| Distance/Speed | 50 feet / 1Mbps | 4000 feet / 1000Kbps |
| RS485 | |
|---|---|
| Transmission Mode | Half Duplex (2 wire)Full Duplex (4 wire) |
| Transmitters | 32 |
| Receivers | 32 |
| Distance/Speed | 4000 feet / 1000Kbps |
Best 1394 FireWire 800 9-pin/6-pin Cable: PASOW FireWire
- Data transfer speeds of up to 400Mbps
- Backward-compatible cable connects FireWire 800 devices to legacy 1394a ports
- Male-to-male connection
- Plug and play
The PASOW FireWire is our choice for the best 1394 FireWire 800 9-pin/6-pin Cable. The cable will work on devices requiring either an IEEE-1394a 400-pin connection or an IEEE-1394b 800-pin connection.
The PASOW FireWire is a popular choice for older Mac products like the PowerBook G4, the 27-inch iMac, the MacBook Pro, and the Mac Mini. Today, you can find a Thunderbolt connection on most Apple products. You can pick up an Apple Thunderbolt to FireWire Adapter to connect your “elder” technology products.
The PASOW FireWire is also a reasonable choice for older digital HDV camcorders, MiniDVs, and DSLRs (Digital Single-lens Reflex.) Not to be forgotten, FireWire was a popular serial connection for external hard drives, DVDs, and CD-ROMs.
FireWire connections are rarely used these days, as they only have data transfer rates of approximately 400Mbps. A USB 4.0 connection has a transfer rate of roughly 40Gbps.
| Pros | Cons |
|---|---|
| It is backward-compatible with older FireWire devices that contain a 400-pin configuration. | The FireWire transfer speed is very slow compared to USB. |
| There’s no need to power down before unplugging the FireWire, as hot swapping is allowed. |
Best USB-C to USB-C Cable: NIMASO USB-C to USB-C
- Fast-charging up to 60W
- Transfer speeds up to 480Mbps
- 4 pack with 4 different lengths: 1foot, 3.3feet, 6.6feet, and 10feet
- 20,000+ bending test
The NIMASO USB-C to USB-C charging cable is our go-to choice for USB-C to USB-C devices. Capable of 60W charging (from a charging device) and data transfer at speeds up to 480 Mbps, it’s hard to complain about a USB-C connection!
A USB-C to USB-C charging cable is the best choice for the latest generation of Samsung Galaxy, Ultra Note, Google Pixel, iPad, MacBook, Chromebooks, and many others.
USB cables have slowly replaced serial cables and connectors. In a perfect world, there would be a single connection that fits all types of technology. We’re not quite there yet!
| Pros | Cons |
|---|---|
| The USB-C connection type is slowly becoming the industry standard. | Not all USB-C ports and cables provide the same power or data transfer rates. |
| USB-C allows fast device charging. | |
| USB-C provides fast data transfer with max rates running around 40Gbps. |
Best for USB-A to USB-B: Amazon Basics USB-A to USB-B 2.0 Printer Cable
- USB Type-A male to USB Type-B male cable
- USB 2.0
- Gold-plated USB connecters for additional corrosion resistance.
- Transfer speed: 480Mbps
The Amazon Basics USB-A to USB-B 2.0 is our selection for computers with a USB-A port that needs to be connected to a USB-B port. The cable has a male serial connection on each end.
The Basics USB-A to USB-B is suitable for external hard drives, printers, cameras, keyboards, or a mouse. You’ll have transfer speeds up to 480Mbps.
A USB-A to USB-B is the most common serial cable and connector configuration for printers and external hard drives. As odd as it sounds, the USB-B connector was designed with its odd size and shape to keep us from inserting the cables into the incorrect devices.
We expect that over time the USB-B port will disappear from printers completely. Most printers no longer ship with a USB-A to USB-B cable. Many users wish to print wirelessly rather than through a physical connection.
| Pros | Cons |
|---|---|
| The same cable can use used for printers, scanners, and external hard drives. | The data transfer speeds for USB Type B are slower than USB Type A or Type C connectors. |
| Physical connections are becoming obsolete as wireless printing becomes the norm. |
Best for USB-C to USB-A: Amazon Basics USB-C to USB-A 2.0 Male Charger Cable
- Data transfer speeds up to 480Mbps
- Up to 15W power output
- Charges and powers USB-C-enabled devices
- Compliant with USB 2.0 standard
The Amazon Basics USB-C to USB-A is a solid selection for laptops, power banks, chargers, MacBooks, and cell phones. A USB-C to USB-A connection provides the flexibility to use older desktops, laptops, or wall chargers to top off your device.
You can connect USB-A devices such as power banks, external hard drives, wall chargers, and laptops to USB-C devices like MacBooks and phones. The USB-C to USB-A remains the most popular serial cable and connector. As older laptops and desktops are replaced with newer computers, USB-C will become the most common USB connection.
| Pros | Cons |
|---|---|
| A USB-C to USB-A is the most versatile connection. | Not all USB-C cables perform the same, even though they may look the same. |
| It can charge and power USB-C-enabled devices. |
How to Pick the Best Serial Cables and Connectors: Step by Step
Depending on your end goal, there are two different processes for selecting the best serial cables and connections. Let’s take a look.
RS232, R422, RS485, or FireWire
Before purchasing serial cables and connectors, take a step back from your project and ask yourself how you visualize the project proceeding once you connect the cable.
If you’re connecting an RS232 or FireWire cable, the odds are very high that you’re connecting an older piece of technology. Are there software drivers available for your current desktop/laptop to allow you to use the hardware you’re connecting to? We’ve used generic drivers ourselves and had successes and failures. The hardware connection of attaching the serial cable is most likely the easiest part of your project.
- Determine the correct pin connectors for both ends of the RS232 serial cable. You’ll need to look at the pin input/output connection terminals to determine the pin count.
- The most common RS232 pin configuration is nine pins (RS232 DB9). Here are the pin specifics.
- RS232 defines the standard data transfer protocol
- D equals the shape of the connector
- B equals the size of the connector
- 9 is the number of pins
- If you want to use a serial cable and connector on a desktop computer that lacks a serial port, you may be in luck. Check if the motherboard on your computer has an open slot that allows for a serial connector to be added. If so, you can add a new serial port. If not, you’ll need to use a USB to serial connection.
- Do you need a male or female connector for each end of the serial cable? Luckily for you, even if you have an unusual connection situation, you can pick up an adapter to help out.
USB
USB connections have replaced RS and FireWire connections because they’re easier to use, have faster transfer speeds, and have larger power transfer capabilities, as shown below.
| Configuration | Version | Max Speed |
|---|---|---|
| Type-A | 2.0 | 480Mbps |
| 3.0 | 5Gbps | |
| 3.1 (Gen 2) | 10Gbps | |
| Type-B | 2.0 | 480Mbps |
| 3.0 | 5Gbps | |
| Type-C | 2.0 | 480Mbps |
| 3.0 | 5Gbps | |
| 3.1 (Gen 2) | 10Gbps | |
| Micro-B | 2.0 | 480Mbps |
| Mini-A | 2.0 | 480Mbps |
| Mini-B | 2.0 | 480Mbps |
| Mico-AB | 2.0, 3.0 | 480Mbps, 5Gbps |
If you’re like us, all the different types of USB serial cables and connections need to be clarified! More than once, we’ve taken our broken cable, usually a mini or micro configuration, to the store to verify that we’re purchasing the correct replacement.
Most devices have a USB port, so you will have to determine what type of connection you need on each end of the serial cable. The chart below is a quick visual reference to the different USB connector shapes.
©zuperia/Shutterstock.com
What to Know Before Buying Serial Cables and Connectors
It would be best if you did some homework before purchasing serial cables and connections. Know the kind of cable and connection you need. One size does not fit all devices and applications.
Older RS232 and FireWire device types like camcorders, DLSR cameras, printers, and scanners have dated technologies and capabilities. It may be difficult, if not impossible, to find updated drivers that will allow older devices to work. Also, think about whether you will be happy with the print quality of a twenty-year-old printer.
USB is a much more current technology when compared to RS232-era serial cables and connectors. Over time, the USB-A and USB-B connectors will become obsolete. If you’re purchasing a new computer today, verify that it has USB-C ports, not just USB-A or USB 3.0 ports.
Using Serial Cables and Connectors: What It’s Like
Using a laptop or desktop with serial cables and connectors should be relatively lag-free and robust. Serial cables and connections allow you to bypass a wireless network that may have network interruptions.
If you’re connecting older devices, you may experience challenges during the device configuration that require a bit of head-scratching and investigation. Connecting current devices with USB technology should be a much more integrated process.
- OIKWAN USB to RS232
- USB 2.0 to RS232 male DB9
- Supports data transfer speeds up to 1Mbps
- FTDI USB serial with the latest FTDI chipset
- Geared for devices such as GPS, routers, serial modems, barcode scanners, label writers, digital cameras, and card readers
- OIKWAN USB C to RS232 DB9 Serial Port Adapter Cable
- USB-C male, RS232 DB9 male
- FTDI-FT232RL chipset
- Plug and play after driver installation
- Great for cash registers, modems, bar code scanners, label printers, digital cameras, and more
- DTech USB to RS422 RS485 Serial Port Converter Adapter Cable
- Connect your RS485 or RS422 device to your computer's USB port
- FTDI FT232 chipset
- Supports Windows versions 7-11, Mac, and more
- Plug-and-play
- PASOW FireWire 800 to 400 9 to 6 pin Cable
- Data transfer speeds of up to 400Mbps
- Backward-compatible cable connects FireWire 800 devices to legacy 1394a ports
- Male-to-male connection
- Plug and play
- NIMASO USB C to USB C Fast Charging Cable
- Fast-charging up to 60W
- Transfer speeds up to 480Mbps
- 4 pack with 4 different lengths: 1foot, 3.3feet, 6.6feet, and 10feet
- 20,000+ bending test
- Amazon Basics USB 2.0 Printer Cable, A-Male to B-Male
- USB Type-A male to USB Type-B male cable
- USB 2.0
- Gold-plated USB connecters for additional corrosion resistance.
- Transfer speed: 480Mbps
- Amazon Basics USB Type-C to USB-A 2.0 Male Charger Cable
- Data transfer speeds up to 480Mbps
- Up to 15W power output
- Charges and powers USB-C-enabled devices
- Compliant with USB 2.0 standard
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We earn a commission if you make a purchase, at no additional cost to you.
We earn a commission if you make a purchase, at no additional cost to you.
We earn a commission if you make a purchase, at no additional cost to you.
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