RS232 Optical Isolator Standard
3-wire

Why use a RS232 Isolator?

The main reason for using a RS232 Isolator is to protect your RS232 devices against high-voltage spikes and surges. The RS232 isolator does this by sending the RS232 signals through optical diodes, also called opto-couplers. The RS232 isolator opto-couplers convert the RS232 signals to light signals, this way there is no actual electrical connectivity between the two isolator RS232 interfaces, only light signals are transferred inside the RS232 ioloator opto-couplers, which gives a very effective protection against all voltage spikes. But not only does the RS232 isolator protect against voltage-spikes, a good RS232 isolator also protects against ground-loops which usually are lower voltage surges over a prolonged time period. However, if you have a long-range RS232 communication line, for example between two buildings, a standard RS232 isolator might not be sufficient protection for example in case the line gets struck by lightning. In that case you might need a RS232 surge suppressor instead of a RS232 isolator. Compared to the RS232 isolator the surge suppressor works more like a fuse, it has an internal gas-tube which blows and at the same time leads the over-voltage to a proper ground. The standard RS232 isolator is however usually recommended in most cases for indoor use. The RS232 isolator effectively protects all devices, equipment and data lines against most common voltage spikes and ground loops.
One last thing to mention about this RS232 isolator is that it is port-powered, this is a convenient feature because in most cases it allows you to simply insert the RS232 isolator between your existing cables. This particular RS232 isolator draws its power from the RS232 interface without interfering with the actual communication signals. By the way, this RS232 isolator isolates and protects three signals: TX, RX and GND, some RS232 isolator units only protects TX and RX and other RS232 isolator units protects all eight serial signals.