HBCR-2210 Datasheet, PDF (3/15 Pages) Agilent(Hewlett-Packard) – Programmable Bar Code Decode ICs

data from hand held laser
scanners with the opposite logic
states: black = low, white =
high. The scanner type pin (SCT)
on the HBCR-2210 series must be
driven prior to power up or hard
reset to identify the type of
scanner connected.
In the HBCR-2210 series ICs, the
automatic laser shutoff feature
delay time is adjustable as a con-
figuration option. Applications
which require increased accuracy
may need the redundancy check
feature.
Scanner input can be disabled by
software command. This allows
an application program to control
when an operator can enter data,
preventing inadvertent data entry.
It also allows the program to
verify each scan before enabling
subsequent scans. The HBCR-
2210 series also offers two Single
Read Modes which allow the
application program to stop bar
code data entry until a “Next
Read” command is received,
allowing the host computer to
process data transmissions before
enabling subsequent reads.
Configuration Control and
Non-volatile Storage
Configuration of the decoder IC
is done by any of three methods.
A minimal subset of key options
can be “hardwired” – controlled
by electrically strapping specified
pins on the decoder IC itself.
Which pins affect configuration
depends on the selection of serial
or parallel interface. Alternatively,
ASCII characters in the form of
HP Escape Sequences (a format
common to HP decoder ICs) can
be sent to the serial or parallel
I/O port; these commands can be
used to control all configurable
options. A third method is optical
configuration, which makes use
of special bar code menus sup-
plied by HP. Menu labels can be
created to modify any configur-
able options. A summary of the
decoder IC features and
applicable configuration methods
for each is presented in Tables 2
and 3.
Once configuration has been set,
it can be stored in an optional
non-volatile memory, if included
in the decoder circuit. When the
EEP pin is tied high, the decoder
IC drives I/O lines compatible
with the widely available 9346/
93C46 family of serial EEPROMS.
The configuration is thereby
saved during power down of the
system and automatically
reloaded at power up. Escape
sequence commands allow
explicit storage and recall of
configuration settings. When
using optical configuration,
storage is automatic. If the EEP
pin is tied low, the EEPROM is
not used, so only hardwired
configuration options are saved
through powerdown; all others
are set to default values at
powerup. Table 2 shows default
values of all features.
Data Communications
The serial port supports a wide
range of baud rates, parities, and
stop bits as described in Table 2.
Software control of data trans-
mission can be accomplished
with a standard Xon/Xoff (DC1/
DC3) handshake. The decode IC
also supports an RTS/CTS
hardware handshake.
The parallel port data has config-
urable parity. When the SMD pin
is tied low, several pins pertain-
ing to the serial port change
function to control a parallel port
instead. Pins 1 through 5 on DIP
packages assume the function of
handshake lines for the parallel
port. The port itself is an external
'646 family octal bus transceiver.
Processor pins 10 and 11 (TXD
and RXD in serial mode) now
control the transceiver chip along
with pins 16 and 17, RD and WR.
Alternative circuits using SSI
latch chips can be substituted for
the '646 implementation to
customize the function of the
parallel port to a particular bus
configuration.
Feedback Features
Both audio and visual feedback
are possible with the HBCR-2210
series. In both cases, the outputs
from the ICs should be buffered
before driving the actual feed-
back transducer. An LED or
beeper connected to the decoder
IC can be controlled directly by
the IC, with signals generated by
successful decodes, or can be
controlled by the host system. In
addition, the tone of the beeper
can be configured to be one of 16
different frequencies, or can be
silenced.
Power Requirements
The decoder IC operates from a
+5 volt DC power supply. The
maximum current draw is 18 mA.
The maximum power supply
ripple voltage should be less than
100 mV, peak-to-peak.
Handling
Precautions
The decoder ICs are extremely
sensitive to electrostatic
discharge (ESD). It is important
that proper anti-static procedures
be observed when handling the
ICs. The package should not be
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