Epson CD5220 - Manual (Page 7)

CD5220 customer display
4. INTERFACE SPECIFICATIONS
4.1
Communication
4.1.1 Serial port (RS232C) communication
(a) The interface specification are based on EIA RS232C baud rate 9600 or
4800 bps ( select by DIP switch, refer Table 4-7) 8 data bits, none parity, 1
or more stop bits
(b) Serial port (RS232C) communication flow
1. Data flow : PC/host to display, display to printer, printer to
PC/host
2. Control flow : display to PC/host, printer to display, PC/host to
printer
(c) CD5220/CD6220 will inactive DTR or RTS signal to PC/host, the
following two condition.
1. Printer inactive DTR or RTS signal.
2. The pass through buffer in CD5220/CD6220 is full ( 200bytes ) .
* If PC/host keep transmitting the data to printer when CD5220/CD6220
inactive DTR or RTS , data will be lost.
4.1.2 Parallel port (Centronic) communication
(a) data flow : PC/Host to display, display to printer
(b) control flow : printer to display , display to PC/Host
(c) When data has been transmitted to printer by parallel port interface, the
CD5220/CD6220 response the printer status to PC/Host, When printer
active the BUSY signal, CD5220/CD6220 will keep accept the data until the