Function: RS485 port with full-duplex or half-duplex operation.

Form factor: M1S

Category: Input/output module

Special needs: [SER]

Power requirements: 5V/15mA

Mates with: #19, #20, #21



Details:

This port has only +/-RX and +/-TX signal pairs. If you are working in the half-duplex mode, connect +RX to +TX, and -RX to -TX. This will allow your system to communicate over a single twisted pair. Direction control is through the RTS line -- the line shall be LOW for data input and HIGH for output. Keep the RX and TX pairs separate for the full-duplex mode and set the RTS line HIGH to keep the TX enabled at all times.

For "normal" RS485 applications, this Tibbit has to be connected to the TX and RX lines of the CPU's UART (see [SER]).

Combine this Tibbit with terminal block devices -- #20 (nine terminal blocks) or #21 (four terminal blocks).

LEDs

There are three LEDs: two red and one green. Red LEDs are connected to TX and OUT/-IN lines. The green LED is for the RX input.