IBM 4685-L0D, Setup, Operation, And Service Manual

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Signaling characteristics
Signals can be transmitted at bit rates of 300, 1200, 2400, 4800, 9600, or 19,200
bits per second. Data is transmitted in asynchronous full-duplex serial mode. Each
data element (character) is transmitted in the following order: one start bit, seven or
eight data bits, one no/odd/even/mark/space parity bit, and one or two stop bits.
The start bit is logic “0,” and the stop bit is logic “1.”
Device requirements
Interface connection
The interface connection is specific either to the POS unit or to the scanner:
The circuit connector at the POS terminal is specific to the POS unit.
The pin assignments at the POS terminal are POS specific but must conform to
the EIA RS-232 standards.
The connector pin-out information is specific to each scanner.
Isolation
The interface must be isolated as follows:
The shield (CHASSIS GROUND) and the logic ground (SIGNAL GROUND)
must be separate.
The following is recommended:
A 360-degree screen conduction
Voltage and current requirements
The voltage and current requirements must conform to the EIA RS-232 standards.
Default values
Property Value
Bit rate 9600 bps
Data bit 8
Parity None
Stop bit 1
Flow control None
4-4
IBM 4685-L0D Scanner: Setup, Operation, and Service Guide