Key Features, Automatic or manual modes | Black Box RS-232 instruction

Black Box Corporation • 1000 Park Drive • Lawrence, PA 15055-1018 • Tech Support: 724-746-5500 • www.blackbox.com • e-mail: info@blackbox.com

RS-232 FALLBACK SWITCH

Y PRIMAR

	RS-232	FALLBACK	SWITCH
		FALLBACK

PRI			TIVE
	ALT		TIVE
	ALT	ALTERNA

AUTO

End transmission downtime with automatic modem switching.

Key Features

Make your system more reliable by switching to a backup modem when your primary link fails.

Minimize downtime and inconvenience.

Flexible—can perform either manual or automatic changeover switching.

Front-panel LEDs show you system status at a glance.

Supports rates as high

as your RS-232 line can carry.

230-volt version available.

Breakdowns in your data communication are always

inconvenient—and often expensive. Our RS-232 Fallback Switch gives you another way to get your vital data through with the least amount of downtime.

By diverting the traffic from a primary modem to a backup modem when the preferred communications pathway fails, the RS-232 Fallback Switch keeps your data flowing. And because the switchover is fast, efficient, and highly reliable, you’re given that extra bit of assurance that your essential information will be there when it needs to be.

Ideal for switching your data from a dedicated leased-line modem to a dialup modem when the leased line goes down, the device switches all 12 leads that are normally required for sync or async operation. What’s more, it can support data rates as high as your RS-232 cable can carry.

Automatic or manual modes

The RS-232 Fallback Switch also gives you several switching options, providing flexibility as your system requirements change. You can operate the switch manually (physically switching between modems as needed), but it also has two automatic modes of operation: normal fallback (FB) mode and autoswitching (AS) mode, which you can customize by setting jumpers inside the unit.

Preset to operate in FB mode, the switch normally communicates with the modem attached to its PRIMARY connector. But, during automatic operation, the RS-232 Fallback Switch also checks constantly for the presence of a “trigger signal” on its ALTERNATE connector. And if one is sensed—whether it’s DSR (Data Set Ready, Pin 6), CTS (Clear To Send), or Carrier Detect

(CD), depending on which of these you select—it’ll switch to the modem attached to that connector. (This switch occurs even if the primary modem is still operating.) When the switch no longer senses the trigger signal, it “falls back” to the primary modem.

In contrast, if you set the switch’s jumper to AS mode, the RS-232 Fallback Switch doesn’t give either the primary or alternate channel higher priority than the other; it switches to whichever modem raises the trigger signal first, and won’t switch back to the other modem until the currently connected one drops the trigger signal.

Simple to set up and operate

Once the switch is configured, simply install it in a cool, dry place close to the devices you want to attach to it and connect the necessary cables. This simple

1	12/18/2003	#11110
1

RS-232 specifications

Black Box RS-232 is a versatile device designed for serial communication using the well-established RS-232 standard. The RS-232 standard has been a cornerstone for serial communication since its introduction in the 1960s and is widely used in various applications today.

One of the main features of Black Box RS-232 devices is their ability to communicate over relatively long distances, up to 50 feet or more, while maintaining clear and reliable signal quality. This capability makes it ideal for connecting devices like computers, modems, and other serial peripherals in environments where distance could pose a problem.

Another key characteristic of Black Box RS-232 products is their support for both hardware and software flow control. This flexibility allows users to choose the best method for managing data transmission, preventing data loss and ensuring efficient communication. Additionally, many Black Box RS-232 devices are configured to support multiple baud rates, which allows them to communicate at varying speeds, accommodating different devices and requirements.

Black Box RS-232 devices often come equipped with multiple ports, which can support simultaneous connections to various devices. This multitasking ability is particularly beneficial in industrial and commercial settings where numerous devices need to communicate with a central control system.

The technology behind Black Box RS-232 incorporates robust signal processing capabilities to reduce noise and ensure data integrity. This is particularly important in settings where electromagnetic interference (EMI) could compromise communication reliability. Furthermore, some Black Box RS-232 products feature built-in diagnostics tools that help users troubleshoot potential issues quickly, enhancing overall productivity.

In terms of physical characteristics, Black Box RS-232 devices are typically compact and durable, making them suitable for both desktop and rack-mounted installations. Their design often includes user-friendly interfaces that simplify setup and configuration, making them accessible even to those with limited technical expertise.

In summary, Black Box RS-232 offers a reliable, flexible, and robust solution for serial communication needs. Its key features, including long-distance communication capabilities, support for diverse flow control methods, multiple port configurations, and noise-reduction technologies, make it an invaluable asset in a range of applications from industrial automation to data acquisition in scientific settings. This combination of reliability and versatility solidifies Black Box RS-232 as a preferred choice for businesses and industries relying on effective serial communication.