40496501TH Rev.1 2102.3.1.2 FunctionAfter the settings outlined in Section 3.3.1.1 are completed and power is turned on, the serialinterface checks the message buffer memory and interface driver/receiver circuit. It then printscharacters.To start and stop this test, push the SEL switch on the front of the printer.Details of this test are explained on the next page.(1) The program revision using two numerical characters is printed.(2) “LOOP TEST” is printed.(3) Memory is checked for the message buffer.(4) Prints “OK” is printed if the memory check is OK and “BAD” is printed if the memory checkfails.(5) Output level to DTR, RTS, and SSD signals is dropped low. If DSR, CTS, or CD signals isHigh, “IF BAD” is printed. If DSR, CTS, and CD signals are all Low, “IF OK” is printed.(6) Output level to DTR, RTS, and SSD signals is raised high. If DSR, CTS, or CD signals is Low,“IF BAD” is printed. If DSR, CTS, and CD signals are all High, “IF OK” is printed.(7) Transmits characters codes from 20H to 7FH is transmitted by SD signal. At the same time,characters are received by the RD signal and stored in the message buffer.(8) The characters that were stored in the message buffer as indicated in (7) are printed.(9) Steps (1) through (8) are repeated until test is interrrupted.
