Very usefull manual. From my point of view there are needs more clearables images.
Text excerpt from page 10 (click to view)
5. To check the 3 Pin I/F After pressing â 7 â button, the following menu appears on the LCD.
PX-653 TEST Program Ver.2.21
7....RS-232C I/F Set the H/T on the I/O box. Select the I/F switch to 3 pin SIF. Press â Enter â key. This test is executed o n c e . In case you want to check this continuously, select aging test at test mode menu.
Set the H/T(DT-9000) , I/O box (DT-9060I/O) and loop back connector as follows;
Loop back connector
6. AGING TEST This test can be check the RS232C I/F and 3 pin I/F. When you select the aging test at test mode menu, you can check the I/F continualy. Each preparation is same for individual test.