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This FTDI converter cable provides a fast, simple way to connect devices with an RS485 interface to USB. Simple Wiring: RS-485 typically requires only two twisted-pair wires for communication. RS-485 does not specify any connector or pinout. Because we chose the default baud rate (which the terminal is presumably already set for), you can simply move the serial cable from the Serial Port 1 connector to the Serial Port 2 connector on the Docking Panel to complete the change to the new port. Resistive termination - If the PDQ Board is at the end of the RS485 cable you can terminate the cable by installing jumper caps at both jumper locations, "Term" and "RTerm". To do that, install a jumper cap at "Term" only. In that case, do not install jumper caps at the jumpers labeled "Term" or "RTerm". In this case, cable connections may be made to Serial 2 on either the 10-pin PDQ Board Serial Communications Header, or the Docking Panel’s 10-pin right-angle Serial Header, or the Docking Panel’s Serial2 DB-9 Connector.

In this case, cable connections may be made to Serial 1 at pins 5 and 6 of the PDQ Board’s 10-pin Serial Header , or pins 5 and 6 of the Docking Panel’s 10-pin right-angle Serial Header. While running this program, the parity settings of Mosaic Terminal may be adjusted, and in each case the message that matches current settings will appear clearly while the other messages will appear garbled. However, verifying correct parity of bytes received with a parity bit is currently not supported. If PT is cleared, then all transmitted bytes with a parity bit will have an even number of total '1' bits. If PT is set, all transmitted bytes with a parity bit will have an odd number of total '1' bits. The M bit, with mask 0x10, determines whether eight or nine bits total are transmitted with each byte, regardless of whether or not the most-significant bit is a parity bit.

So, for eight data bits with a parity bit, M would be set (equal to one) in order to add an extra bit to each byte transmitted, and PE would be set in order to make that extra bit be used as a parity bit. If your application requires communicating with a device that expects to receive a parity bit, the generation of a parity bit and selection of even or odd parity, and whether there are seven or eight data bits in each byte, is performed by setting or clearing bits in the configuration registers SCI0CR1 for Serial1 and SCI1CR1 for Serial2. For seven data bits with a parity bit, M would be cleared (equal to zero), and PE would be set in order to make the most-significant bit of a normal eight-bit byte be used by the serial port as a parity bit. The PT bit, with mask 0x01, determines whether even parity or odd parity is used if parity bit generation is enabled.

When PE is set (equal to one), the most-significant bit in each byte transmitted will be a parity bit that is either set or cleared by the serial port automatically in order to achieve even or odd parity. When PE is cleared (equal to zero), the most-significant bit of each transmitted character will be a data bit. This is an extra single bit appended to the end of each byte or character transmitted, which is set or cleared as necessary to ensure that the total number of '1' bits in the byte is always odd or even. The above parity settings will also determine how incoming data is interpreted (whether the most significant bit is considered a parity bit or part of the data being transmitted, and how many bits total to expect in each byte). 5 should work in your situation because of the voltage you will be running (5-10V) and your signal is not high frequency (above 500Mhz) in the first place. Enabling RS485 on the Serial2 port is parallel to the process described above. For Serial2 RS485 operation: Install the jumper shunt onto "2 485En" (J7). For Serial2 RS232 operation: Remove the jumper shunt from "2 485En" (J7).