Moxa Expands Offering of Ruggedized USB-to-Serial Converters

All too often, a computer upgrade leaves technicians with the difficult task of interfacing legacy devices, since virtually no modern laptops or desktop computers feature serial ports. Therefore, a simple computer upgrade can leave a system without a simple means of connection. Moxa developed the UPort 1400-G2 USB to serial converter to keep legacy devices, such as controllers, barcode scanners, sensors, PLCs, and others in service.

 

USB to Serial Conversion

A quick glance at the pins on a USB cable and a serial cable shows a dilemma. The conversion between USB and serial is not simply making a few pin changes and rearranging connections. The USB cable has four pins and the serial cable (DB9 end) has nine pins, and even those with similar names (Tx and Rx) have completely different functions. This means there has to be some sort of processor with buffer storage space to handle the conversion between USB and serial so that all of the data gets transferred at the appropriate speed for the protocol.

In the past, the processor has been the cause of many problems. More than one person has bought a USB to serial ‘converter’ where the processor did not handle this conversion correctly. Unfortunately, many online outlets are flooded with cheap converters that do not perform this conversion reliably, or with drivers that can be difficult to find, unacceptable for an industrial operation.

 

The UPort 1450-G2 is one of the models in the 1400 series. Image used courtesy of Moxa

 

Moxa UPort 1400-G2 Series

The Moxa UPort 1400-G2 not only performs the conversion correctly and addresses this common problem, but it also has several other distinct advantages.

First, the UPort 1400-G2 has four serial ports, making it much more versatile than the inline cables on the market suitable for only one end device. Therefore, this converter occupies one USB port on the computer, but can interface four separate serial devices (RS-232/422/485). This reduces the amount of cabling required to interface multiple devices.

In terms of design, the UPort 1400-G2 is ruggedized for the industrial environment. Existing models on the market are usually meant for consumer or hobby-level goods and often feature cheap cabling and poorly sealed electronics. In contrast, the UPort 1400-G2 is sealed in an IP20-rated box, capable of withstanding temperatures from 0 °C to 60 °C, or from -40 °C to 75 °C, depending on the specific model. Also, the ‘I’ series converters feature 2 kV of isolation between ports, protecting devices from accidental short or contact with high voltage.

Also, because serial port devices can default to problematic behavior if the cable is unplugged at the wrong time, maintaining connection is paramount to successful interfacing. The UPort 1400-G2 implements latch and screw locks to ensure a secure connection at all times.

 

Front and back view of the UPort 1450-G2 showing the four serial ports. Image used courtesy of Moxa

 

Legacy Devices in Modern Systems

Perhaps an engineer who works in a fully modernized environment might think, “who cares about serial devices?” The author of this article, for one, certainly cares! The best robot in the factory is the one that is performing its duties with little maintenance. Therefore, an ‘old’ robot in the corner of the factory that is performing is still worth keeping around. Often, industrial devices last for decades, but the interfacing computers are subject to failure and upgrade, leading to the conflict in cables and ports. Why discard a reliable device just because the computer that interfaces has failed?

This is the problem that Moxa has solved with the new UPort USB-to-serial converter.