The DB1000 Series Decoder Chip decodes the two most common industrial barcodes, Code 39 and Interleaved 2 of 5. Both the Normal and Extended versions of Code 39 are supported. The decoder reads codes up to 20 characters long. Both serial and keyboard wedge communications are supported. RS-232, RS-422 and RS-485 communications can be achieved with appropriate interface circuits. A polling protocol is built in, enabling the unit to be used in multidrop communications. The decoder will interface with a standard un-decoded laser gun as well as wands and fixed optics scanners. A compare function enables the barcodes being read to be compared to a single value retained in nonvolatile memory. The decoder parameters can be setup by sending commands to the chip via the serial communications port. Default parameters can be set using hardware jumpers.
The DB1000 Series is designed to be incorporated into the users printed circuit board. The unit is available in either PLCC-44 or 40-pin DIP packages. No external memory or latch chips are required, keeping component count to a minimum. External circuitry includes a crystal, reset/watchdog chip and Serial EEProm. An interface circuit for the desired communications option is also required. A general application circuit is shown below. The Product Manual shows details for various communications and scanner options. Download the Manual in PDF format (19 pages). Good circuit layout practices are required when designing a circuit board, including a decoupling capacitor close to the Vcc and Ground pins.
Power: +5VDC ±5% @ 75ma. Maximum
Digital Input: TTL Level Signal, Bar=1 in Normal Mode,
Bar = 0 in Laser Mode.
Communications: Serial ASCII
Baud Rates: 2400, 4800, 9600, 19200
Parity: Mark, Space, Even or Odd
Stop Bits: 1 or 2
Keyboard Wedge: IBM PC/AT keyboard Interface
Messages: 10 Character preamble and ID character.
Code Types: Interleaved 2 of 5, Code 39
Extended Code 39
Code Lengths: Up to 20 Characters.
Check Character: Supports check characters for
both code types.
Temperature: Operating: 0° to 70°C
Storage: -40° to 70°C