CBM-270 User’s Manual
7. SERIAL INTERFACE

7.1 Specifications

(1) Synchronous system : Asynchronous
(2) Baud rate : 1,200, 2,400, 4,800, 9,600, 19,200 bps (Selected by the user)
(3) 1-word configuration
Start bits : 1 bit
Data bits : 8 bits or 7 bits (Setting upon shipment)
Parity bits :Odd, even, or no parity (Selected by the user)
Stop bits : 1 bit or more
(4) Signal polarity
RS-232C
•Mark = Logic "1" (-3 ∼ -12 V)
•Space = Logic "0" (+3 ∼ +12 V)
(5) Received data (RXD signal)
•Mark = 1
•Space = 0
(6) Reception control (DTR signal)
•Mark : Data not transferable
•Space : Data transferable
(7) Transmission control (TXD signal)
•DC1 code(11H) X-ON : Data receivable
•DC3 code(13H) X-OFF : Data not receivable

7.2 Connector's Pin Configuration

No. Signal Name Input/Output Function
1 FG Frame Ground
7 GND Signal Ground
3 RXD Input Received Data
20 DTR Output Printer BUSY Signal
2 TXD Output Transmitted Data
6 DSR Input Data Set Ready
[Note] 1. The RS-232C signals are based on the EIA RS-232C.
2. The received data should be always maintained in the Mark status when no data is being
transferred.
Applicable connectors (D-Sub connectors)
Printer side :17LE-13250 (Anphenol) or its equivalent
Cable side : 17JE-23250 (Anphenol) or its equivalent

7.3 Input and Output Signals