Epson 890N Service Manual - Page 28

EPSON FX-890/2190 † Main command Table 1-32. Main command Option command number Command name Sending Timing • Init signal on the std. parallel 01h Start Software Reset • Type-B I/F Option command : 01h • Panel Reset 02h Send Option Type 04h Send Name Data • Cold start • Deciding the level of Type-B I/F after power on • Type-B I/F Option command: 05h 07h Inquire Software Emulation Type • Changing control language 0Eh Inquire ASCII Message • Writing to DBIN-register 14h Inquire Emergency Reply 15h Send Emergency Message • Reply for Back Ground Job command response • Receive back Ground Job command † Back Ground Job command: Response "0x00": get device "0x01": get all status "0x02"~"0x3F" ID Normal response Normal response Processing impossible response † A bit rate available by Serial I/F card : 19200bps, 9600bps, 4800bps, 2400bps, 1200bps, 600bps, 300bps Revision B 1.2.6 Interface selection The printer has 3 interfaces; the parallel interface, USB interface and Type-B optional interface. These interfaces are selected manually by Default Setting or selected automatically. † Manual selection One of the three interfaces can be selected by Default Setting. † Automatic selection The automatic interface selection is enabled by Default Setting. In this automatic interface selection mode, the printer is initialized to the idle state scanning which interface receives data at power-on. Then the interface that receives data first is selected. When the host stops data transfer and the printer is in the stand-by state for the period of seconds specified by Default Setting, the printer is returned to the idle state. As long as the host sends data or the printer interface is the busy state, the selected interface is let as it is. † Interface state and interface selection When the parallel interface is not selected, the interface gets info a busy state. When the Type-B serial interface card is installed and it is not selected, the interface sends XOFF and sets the DTR signal MARK. When the optional interface is not selected, the printer sets "OFFLINE" bit of MNSTS register to the optional interface. When the printer is initialized or returned to the idle state, the parallel interface got into a ready state, the serial interface sends XON and sets the DTR SPACE and the printer resets "OFFLINE" bit of MNSTS register to the optional interface. Note that the interrupt signal such as a -INIT signal on the parallel interface is not effective while that interface is not selected. † Preventing Hosts from Data Transfer Timeout Generally, hosts abandons data transfer to peripherals when a peripheral is in the busy state for dozens of seconds continuously. To prevent hosts from this kind of timeout, the printer receives data very slowly, several bytes per minute, even if the printer is in the busy state. This slowdown is started when the rest of the input buffer becomes several thousands of bytes. At last, when the input buffer is full, the printer is in the busy state continuously. IEEE1284.4 on the parallel interface and on the USB interface do not require this function. PRODUCT DESCRIPTIONS Interface 28