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.