In this chapter we will introduce how to use diagnostic programs to prove the PCCOM device driver is active and your serial port is work normally.

7.1 TESTCOM Diagnostic Program

The TESTCOM program provides diagnostic routine to test your serial ports under MS/DOS operating system. It provides internal loopback test and external loop test.

To test your serial port under MS/DOS, please type

A> TESTCOM

then screen will display as follows:

wait a moment, the screen will display as follows:

You may specify communication parameters such as baud rate, data bits ... etc. Since these communication parameters are set up when computer system is boot. However, if you want reset communication parameters, please select setup RS232 function to setup new communication parameters. We provide several preconfigurated file of our multi-serial adapters, which are named *.CFG, you may rename one of these files to TESTCOM.CFG.

2. INTERNAL LOOP TEST

The internal loop test provides a loopback feature for diagnostic testing of the 8250/16450/16550 chip. You may type characters from keyboard, then the received character is display on the screen. When something error such as time out, frame error ... etc., the reversed character will display on the screen to indicate communication fail. We note that some 16450 chip will not emerge an interrupt when loopback feature is selected.

3. EXTERNAL LOOP TEST

When you select external loop test, your typing characters will be sent from one serial port to another serial port. Before you select external loop test, please connect pin 2 of send port to pin 3 of receiver port and pin 3 of send port to pin 2 of receiver port. Since the serial communication is full duplex, you can loopback send and received port in one port.

a. Connects two rs232 ports

pin 2 TxD RxD pin 3

pin 3 RxD TxD pin 2

b. Loopback

pin 2 TxD

pin 3 RxD

4. AUTO TEST

When you select auto test, the TESTCOM will test your serial port automatically. Both internal loop test and external loop test are used to check the selected port. The sending character are read from README.DOC file.

5. SAVE CONFIGURATION

Save communication parameters to disk file. When TESTCOM is loaded, it will load the preconfiguration from disk file. The configuration file name is TESTCOM.CFG.

You can use <RETURN> key to let TESTCOM accepts your selection during you execution the TESTCOM program, and press <ESC> key to return the last menu.