1) HOW IS A LOOPBACK TEST PERFORMED ON A SERIALCOMM USB TO RS485/RS422 ADAPTER RUNNING IN RS485 MODE?
Answer: The USB to RS485/RS422 Adaptor (in RS485 mode) loopback test requires two USB to RS485/RS422 adaptors to perform the test. Connect the two adaptors to two PC USB ports. Cable the RS485 connections on the adaptors to each other [Pin 2 (T/R+) to Pin 2 (T/R+), and Pin 1 (T/R-) to Pin 1 (T/R-)]. Run two instances of any HyperTerminal software (such as AccessPort, a free download available on the SerialComm website under the downloads menu). Setup each HyperTerminal to operate one of the adaptors. Setup both HyperTerminals’ baud rate, data bits, parity bit, and stop bits identically. Then send data out from one HyperTerminal to the other. The data should be visible on the receiving HyperTerminal. Repeat the test in the other direction. This procedure tests both the receive and transmit functions of both adaptors