Plug-On Board enables 1.2 km point-to-point transmission.

Press Release Summary:

Designed to adjust serial interfaces on SMA modules, RS232 Piggyback Model 422S4B-G1 allows point-to-point connection over distance of 1.2 km. By using piggyback, interface signals TxD, RxD, RTS, and CTS of serial interface module are converted and electrically separated into differential RS422 levels. Receive lines of RS422 interface are terminated with 120 Ω on piggyback and equipped with 680 Ω bias resistors to apply greater than 200 mV voltage level.

Original Press Release:

RS232 Piggyback for Point-to-Point Transmission

Fountain Valley, CA, November 18, 2005 - Data transmission via serial inter-faces is both a simple and safe method to connect computers with each other or with peripheral components. In order to exploit all possibilities of this communication method, SMA has developed a range of plug-on boards, called piggybacks, that are able to adjust the serial interfaces on SMA modules according to the various physical standards. Now available from SMA is a special RS232 piggyback allowing a point-to-point connection over a distance of 1.2 km.

Point-to-Point Transmission over 1.2 km
Serial data transmission according to the RS232 standard represents the simplest way of ex-changing data between two participants. But, when using this standard, the cable length is limited to approximately 20 meters. In order to use this simple point-to-point connection over larger distances, SMA now announces a piggyback which enables connections over a distance of up to 60 times this far. This technology can be used with all SMA modules that have serial interfaces. By using the "422S4PB-G1" piggyback, the interface signals TxD, RxD, RTS and CTS of the serial interface module are converted and electrically separated into differential RS422 levels.

The receive lines of the RS422 interface are terminated with 120 Ohm on the piggyback and equipped with bias resistors (680 Ohm) in order to permanently apply a valid voltage level (> +200 mV) to the receiving module. The RS422 signal levels make it possible to transmit data over a distance of up to 1.2 km when using suitable cables. The piggyback must be installed on each component. The 422S4PB-G1 piggyback is available for $78. For details see

North American Sales Contact:
George Renth
Vice President, Sales and Operations
SMA Computers
9550 Warner Ave., #250
Fountain Valley, CA 92708
Phone +1 714.593.2338
Fax +1 714.593.2368

European Sales Contact:
Wolfgang K. Weber
Manager, Sales and Marketing
Communication & Control
SMA Technologie AG
Hannoversche Str. 1 - 5
34266 Niestetal
Phone +49 561 9522 - 112
Fax +49 561 9522 - 103

More from Controls & Controllers

All Topics