Bixolon SRP-350 User Manual

Page of 59
 
Rev. 2.01 
- 26 -
SRP-350/352plusA&C
3-5-1(e) H/W Flow Control 
When DTR/DSR flow control is select, before transmitting a data, the Printer checks whether the host is 
BUSY or not. If the host is BUSY, the Printer does not transmit a data to the host. If the host is not BUSY, the 
Printer transmits a data to the Host. The host is the same. Refer to the Interface Part of Chapter 7 (Special 
Circuit Diagrams). 
 
3-5-1(f) S/W Flow Control 
When XON/XOFF flow control is selected, the printer transmits XON(ACSII 11h) or XOFF(ASCII 13h) signal 
through the TXD line. 
If the Printer is BUSY, the Printer transmits XOFF(ASCII 13h) to host through the TXD line. Then the host 
recognize that the Printer is BUSY. So, the host does not transmit a data to the Printer. If the Printer is 
released from BUSY, the Printer transmits XON(ASCII 11h) to host through the TXD line. Then the host 
recognize that the Printer is not BUSY. And the host transmit a data to the Printer. 
 
 Note : Refer to the Operation Manual about XON/XOFF flow control. 
 
 
 
 
3-5-2 IEEE1284 Parallel Interface 
 
Bidirectional parallel interface : in accordance with the IEEE1284 Nibble/Byte mode. 
 
2-5-2(a) Forward Mode Specification (Compatibility mode) 
Data transmission from host computer to printer : Centronics compatible 
 
Item 
Description 
Remark 
Data Transmission 
• 8-bit Parallel 
 
Synchronization 
• External supplied nStrobe signals 
 
HandShaking 
• nACK and Busy signals 
 
Signal Level 
• TTL compatible 
 
Connector 
• Centronics 36P 
 
Table 3-16 IEEE1284 Specification 
 
3-5-2(b) Reverse Mode Specification (Nibble / Byte mode) 
Data transmission from the printer to the host computer. 
The STATUS data transmission from the printer to the host computer is accomplished in the Nibble or Byte 
mode. This mode allows data transmission from the asynchronous printer under the control of the host 
computer. Data transmission in the Nibble mode are made via the existing control lines in units of for bits 
(Nibble). In the Byte mode, data transmission in accomplished by making the 8-bit data lines bidirectional. 
Neither mode can operate at the same time as the compatibility mode, so switching is always required.