232/422 converters


Thread Starter

Peter Davidson

I have a requirement to convert and optically isolate an RS422 signal to RS232 - not a big problem - but the pulse width of the 422 signal is approximately 2.0 to 2.5us, which means that I need to find a converter that will operate at a baud rate of around 500kbs. Most that I see are around 115k max -

Any pointers anyone?

1) does your equipment actually talk at 500Kbps?
2) contact various convertor manufactures and see what they have to say.

Most likely a device which is designed to take serial data to optical is going to work just fine.

Robert Scott

...Not necessarily. Some are too slow. Look instead to the kind of isolators that are used in 500 Kbs CAN bus applications. They have to be very fast.

Robert Scott
Real-Time Specialties
Embedded Systems Consulting.
Typically, RS-232 ports run at 115.2K bps max. which is why most interface converters are restricted to that speed. Sealevel Systems offers several optically isolated serial products (including USB and PCI) that will operate in RS-422/485 mode at up to 921.6K bps. Their tech support staff can help you further.