PC connection over fiber-optic cables
Background knowledge: Power for the interfaces
The interface type described on this page is powered from the signal lines of the serial interface and generally requires no external power supply to operate on standard RS232 interfaces.
If however there are supply problems due to low-power interfaces, it is always possible to externally power the interface with up to 9V using its handshake inputs, or to use fiber-optic interfaces having their own power supply (e.g. model 81201).
With model 81029 there is also a 9-pin special version available whose transmission distance is limited to from 0 to 20m, but which only places an approx. 2mA load on the connected RS232 interface. With this version it is also possible to run on lower power RS232 interfaces without the need for an additional voltage source.
Background knowledge: Transmission distances
The limitation with respect to a minimum required fiber optic cable length of 5 meters is only relevant when using the maximum baud rate of 115.200 baud while simultaneously running the interfaces on RS232 ports with low output voltages.
If any of these limiting conditions does not apply, the Interfaces (e.g. for galvanic isolation of serial ports) can also be operated using very short fiber optic cable lengths.
Due to the current-saving construction of model 81029 we recommend in such application cases still using this Interface type, since the connected RS232 ports are only minimally loaded.