USB vs Serial and Parallel
USB vs. Serial and Parallel

Contents

Total Phase is pleased to offer USB on all its devices. USB is the standard for connecting peripherals to your computer. Additionally the Promira Serial Platform includes a 1 Gigabit Ethernet port.

Comparison

Here is how USB stacks up against other protocols available for other host adapters:

 USB 3.1 Gen 2USB 3.1 Gen 1 (USB 3.0)USB 2.0USB 1.1SerialParallel
Industry StandardYesYesYesYesYesNo
Bandwidth10 Gbps5 Gbps480 Mbps12 Mbps115 Kbps115 KBps
EPP/ECP - 3 MBps
Number of Devices127 devices on a single USB bus127 devices on a single USB bus127 devices on a single USB bus127 devices on a single USB busLimited to the number of ports available on the computer.Limited to the number of ports available on the computer.
Bus PowerYes, can provide up to 900 mA at 5V (Also USB Power Delivery)Yes, can provide up to 900 mA at 5V (Also USB Power Delivery)Yes, can provide up to 500 mA at 5VYes, can provide up to 500 mA at 5VNoNo
Cable Length LimitCable can be of any length as long as electrical spec is met. Practical max length is 1m.Cable can be of any length as long as electrical spec is met. Practical max length is 3m.5 m / 16 ft5 m / 16 ft3 m / 10 ft1.8 m / 6 ft
Plug'n'PlayYesYesYesYesNoNo
Hot SwapableYesYesYesYesNoNo

Serial

The serial port does not suffer the same problems of the parallel port. The behavior of the serial port has been standardized across computers so there are no surprises there. The real problems are: bandwidth and limited ports. The serial port is the slowest of the group. If you have a host adapter that claims to support 400 kbps, consider the fact that the serial port can only support 115 kbps. That just doesn't add up.

Parallel

The Parallel port can be fast enough for most applications, but it suffers from many problems. The most significant issue is that the port is non-standard. Often times, users of the parallel port will run into OS issues or BIOS issues. And good luck trying to use the parallel port on your laptop computer. Most manufacturers have different implementations of the parallel port. On most computers there is usually only one parallel port available which can cause many headaches if that port needs to be shared with a printer or scanner.