Why would I want or need an RS485 TO RS232 adapter cable ?
The RS485 to RS232 adapter has been primarily designed to be used with the Actisense Active DST Module and Active Transducer, and future Actisense NMEA 0183 sensors.
It enables these Actisense product's Flash to be updated with the latest software, whenever it becomes available on this website (please refer to the Software section for latest details).
This adapter cable allows easy, safe and low-cost connection of an Actisense NMEA product to a laptop or PC, by matching a standard RS232 D-type 9-pin serial port to an NMEA 0183 type marine bus link.
It needs no external power supply as the interface takes all the power it needs from the computer port. Once the cable is wired to the NMEA interface and the connector is plugged into the computer, the Actisense product will be ready to be reprogrammed.
This adapter contains a full RS485 (automatic) bi-directional interface using just 2 wires. With built in protection against electrostatic discharge (up to 3000 volts), this does not provide the complete protection of the Opto-isolator product, as the ground connection is still common between input and output. However, it will protect a computer against most common noise spikes present on a boats wiring network.
Alternative uses for this adapter cable are possible, although only in 2-wire systems that also require the automatic switchover between receive and transmit modes.
For a more compatible 4-wire adapter between RS422 / RS485 and RS232, with the added benefit of full Galvanic Opto-isolation, please view the NMEA Opto-isolator adapter.