RS-232 transmission distance is limited by cable capacitance. Distances greater than 50' (15.2m) will reduce signal strength, leading to corrupt data and possibly complete signal loss. This makes it unsuitable for reliable long distance communication. The low-cost solution is to convert RS-232 signals to an alternative format. RS-422 and RS-485 can handle 4,000' (1,200m). Fiber optic signals can be sent over much greater distances.
The declining availability of RS-232 ports on computing equipment is another reason for signal conversion. Converting RS-232 serial signals to USB lets a single PC receive connections from one or more serial devices. In some situations, electrical noise will disrupt serial signals and possibly damage sensitive equipment. The solution is an RS-232 repeater providing surge protection.
Serial communication is built into equipment found in many different sectors. It's used in building access control and also in Intelligent Transportation Systems (ITS). In industrial sites, it's used for data acquisition, process control and automation.
Users like sending data to a central location, often for logging on a PC or for decision-making. Lots of older equipment was built with only RS-232 outputs, so long distance transmission requires conversion and possibly reconversion at the receiving end. It's not uncommon to have an RS-232 source converted into RS-422 or fiber optic signals for long distance transmission. Then at the receiving end, it's converted back into RS-232 and finally to USB so multiple devices can communicate with a single PC.
Westward has converters for serial (RS-232/422/485) to fiber, serial (RS-232) to serial (RS-422/485) and serial (RS-232 or RS-422/485) to USB. Manufactured by Antaira Technologies, these are all warrantied for 5 years.
Resistant to EMI, fiber can send signals many miles. The Antaira STF-300C-CM02 is an inexpensive means of converting RS-232/422/485 signals for fiber transmission. For a more robust solution, consider the STF-401C compact industrial serial-to-fiber media converter. DIN-rail mountable, it's a good solution for ITS, process control and industrial automation. Where isolation is required the STF-501C and STF-502C provide superior equipment protection.
Converting the output from RS-232 to RS-422 or RS-485 increases the maximum transmission distance significantly. The STS-1915S performs this conversion and can work as either a client or server, providing RS-422/485 serial communication through the standard RS-232 port.
These let a PC or laptop with no serial port send and receive data. At their simplest, they comprise a cable with a male USB connector at one end and a block incorporating a DB9 connector and conversion electronics at the other. The UTS-1110A handles RS-232 to USB conversion while the UTS-1458B does the same for RS-422/485. When isolation is needed, the UTS-1461A-SI and UTS-401BK-SI perform the same one-to-one conversion but with additional protection.
Similar converters are available for when it's useful to put multiple RS-232 cables into a single USB port. The UTS-402CK has two male DB9 connectors, the UTS-404A has four, UTS-408A has eight and the UTS-416AK accepts 16 RS-232 inputs.
Whether you need an industrial serial or USB conversion, Westward Sales is ready to configure a communication solution that works. Contact us today. We promise a quick and informed response from our team.