Bixolon Receipt Printer SRP-270 User Manual

 

Pin No.  Signal name  Direction 

Function 

1 

Frame GND 

- 

Frame Ground 

2 SD2 

Output 

3 SD1 

Output 

Send Data 
”H” : SD1 > SD2 , “L” : SD1 < SD2 

4 RD2 Input 
5 

RD1 Input 

Receive Data 
”H” : RD1 > RD2 (RD1-RD2 ≥ 0.2V) 
“L” : RD1 < RD2 (RD1-RD2 ≤ 0.2V) 

7 SGND  - 

Signal 

Ground 

8 
9 

DR2 
DR1 

Output 

When DTR/DSR is selected, this signal indicates whether the printer is 
BUSY or READY. (H/W flow control) 
  1) DR1 > DR2 (H) : The printer is BUSY. 
  2) DR1 < DR2 (H) : The printer is READY. 
  3) The host computer transmits a data to the host, 

  after confirming this signal. 

10 

11 

CS2 
CS1 

Input 

When DTR/DSR is selected, this signal indicates whether the host 
computer is BUSY or READY. (H/W flow control) 
  1) CS1 > CS2 (H) : The host computer is BUSY. 
  2) CS1 < CS2 (H) : The host computer is READY. 
  3) The printer transmits a data to the host, after confirming this signal.

Table 3-17 RS-485 Pin Description 

 
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3-5-2(e) H/W Flow Control 
When DR1,2/CR1,2 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 4-3 Special 
Circuit Diagrams. 
 
3-5-2(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. 
 
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3-5-3 IEEE1284 Parallel Interface 
Bidirectional parallel interface : in accordance with the IEEE1284 Nibble/Byte mode. 
 
3-5-3(a) Forward Mode Specification (Compatibility mode) 
Data transmission from host computer to printer : Centronics compatiable 
 

Item 

Description 

Remark 

Data Transmission 

• 8-bit Parallel 

 

Synchronization 

• External supplied nStrobe signals 

 

HandShaking 

• nACK and Busy signals 

 

Signal Level 

• TTL compatiable 

 

Connector 

• Centronics 36P 

 

Table 3-18 IEEE1284 Specification