I have a Symbol barcode module model SE-1200WA-1000A.
It has got an 8-pin connector.
I would like to interface to it from a micro controller or a PC.
Could someone please help me with the pin connections and communication
protocol?
This is an UNDECODED module; you will have to use software to decode
the barcode data. The decoded version is the SE1223. Note: the WA in
the number means Wide Angle.
That said, for what you have, here is the pinout:
1 Power - Supplies power to the engine. 5 VDC ± 10%; approx 60 mA
(130mA max)
2* Range Limiter - When low, scanner range is reduced. When high, or
not connected, scanner operates with full performance. (Also called
Scan/Aim.)
3* Laser Enable - When low, the laser is enabled only if pin 4
is also low. Laser is off if high or not connected.
4* Scan Enable - When low, the scan motor runs and all circuitry is
activated.
5 Digitized Bar Pattern - This output represents the widths of the
bars and spaces in the symbol being scanned. An internal 10K ohm
pull-up resistor is used. Valid DBP data should not be expected for
about 55 msec after both Laser Enable and Scan Enable are active.
high = bar, low = space
6 Start of Scan - This output changes from high to low, or low to
high, when the scanned laser changes its direction of travel at either
end of the scan line. An internal 10K ohm pullup resistor is used.
7, 8 Gnd - Ground
* Minimum impedance between this pin and pin 1 is 1K ohm
From the drawing, it looks like pin 1 on the connector is the side
towards the center of the scan engine. There is usually an
arrow/triangle molded into the connector to indicate pin 1.
Being undecoded, there really isn't much of a protocol. Scan Enable
starts the mirror moving. Laser Enable turns the laser on. You
should start seeing the SOS signal transitioning (indicating mirror
movement). Any changes in the light picked up by the photodiode in
the module are squared up by the (analog) circuitry and sent out the
DBP signal. Your system times the widths of the bars and spaces and
figures out if it represents a valid barcode (of the types you are
interested in).
I hope you have a supply of the little flex cables needed to go in the
connector. Be very careful with the flex connector, as they can
easily break (usually, the little lever/sliding piece pops out and
goes flying - if you are lucky, the retention feature on the connector
hasn't broken and you can carefully put it back together).
Laser Safety. Don't shine the laser onto your or any other creature's
eyes. As long as the mirror is up to speed, you are unlikely to
actually harm anyone's eyesite, but don't take any chances. Your
circuitry should make sure that the laser is shut off if the SOS
signal doesn't transition within a reasonable amount of time (meaning
the mirror isn't moving).
Good Luck!
Mike
