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FMT 3000 Hardware Reference Manual - Introduction
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+5 V power is supplied to the connector. +12 V, -12 V and - 5 V are not provided,
however, a 4-pin Molex style header is provided on the main board to supply these
voltages from an external power source if required.
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DMA channels 0,1 and 2 are supported.
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IRQ7 and IRQ 12 are reserved by the CPU board and are NOT brought out to the
PC/104 connector
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No Bus Master support.
The limitations listed may affect some analog I/O data acquisition PC/104 cards, but
otherwise should have little affect on the use of the expansion site.
Bar Code Decoder
The bar code decoder is implemented using a microcontroller programmed with decode
algorithms. The decoder communicates with the unit through COM3. The communication
parameter settings are fixed at 9600 baud using space parity.
Programming decoder options, such as enabling bar code symbologies or disabling reading
of data from a device, is done by sending various ASCII command codes to COM3. Decoded
input data can be either received through COM3, or “wedged” into the keyboard input
stream, making it appear that the data was typed at the keyboard. See the FMT 3000
Software Manual for bar code programming details. Both fully decoded (more expensive) and
undecoded (less expensive) laser input devices can be used, increasing flexibility and
potentially reducing system cost.
Three separate connectors and signal paths are provided for connection of bar code wands,
slot readers, and laser scanners. Located at the front connector area on the unit is a DB9-pin
connector for bar code readers and a DB9-pin connector for non-decoded lasers. The DB9
connector labeled “Barcode” is for decoded lasers or wand type devices and the DB9
connector labeled “Laser” is for undecoded laser scanners only. Inside the unit’s case is a 5-
pin header for connecting magnetic slot readers. The decoder circuit imposes signal polarity
requirements on devices: bar code and slot devices must be black high, lasers devices must
be white high.
Normally, the decoder operates in a polled fashion, alternately enabling and sampling each
of the three device’s data line looking for data. If only one device is used, the other two may
be disabled to improve performance. Also, bar code symbologies may be eliminated to
increase performance.
The unit also provides for a beep to be generated by the internal speaker or external auxiliary
speaker when a good read of the bar code or laser device occurs. The beep may be disabled