Introduction; Main Security Barriers; Features - Black Box Programmable Security Guard Manual

The Programmable Security Guard (PSG) adds
security to any RS-232 asynchronous port, to help
protect your computer resources from unauthorized
accesses. The PSG is an in-line buffer box with three
modes of operation:
• Security Mode
• Pass-Thru Mode
• Program Mode
After a reset, the unit is in "Security Mode." While
in Security Mode the unit acts as an open switch,
and will not pass any data until certain security
barriers are broken. Once valid users successfully
pass through the security barriers, the unit will
change its mode to "Pass-Thru." In Pass-Thru Mode
the unit buffers data received from each port and
retransmits this data out the other port, using the
configured word structure, data rate, and flow
control of that port. Program Mode is used to enter
and update passwords and other parameters for the
security barriers.

2.1 Main Security Barriers

• Primary password validation
• User's location validation ("callback")
• Secondary password validation

2.2 Features

• Configurable by the user via software
(program mode) and DIP-switch selection.
• 1K of memory available for buffering.
• Each port can be individually configured, via
DIP switches, for word structure (7 or 8 data
bits, even/odd/no parity), data rate (45.5 to
38.4 Kbps), and flow control (X-ON/X-OFF
or DTR/CTS).
• Battery-backed-up memory saves all programmed
information automatically in case the power fails.

2. Introduction

NOTE: These messages can be disabled via DIP
• Program mode for entering primary passwords
and their associated parameters.
• Primary passwords can be assigned to either or
both ports of the PSG, for security protection in
any direction.
• DIP-switch-selectable password retry count
(1, 2, 3, or infinite).
• DIP-switch-selectable maximum time period for
entering primary and secondary passwords (10
seconds, 30 seconds, 1 minute, 2 minutes).
• Internal memory storage of up to 64 different
primary passwords, associated response strings,
and secondary passwords.
• User-programmed primary and secondary
passwords: up to 32 characters long.
• Optional status messages like:
"invalid password"
"primary password accepted, unit now in pass-
thru mode"
"primary password accepted, prepare for user
location validation"
"primary password accepted, enter secondary
password"
"secondary password accepted, unit now in
pass-thru mode"
switch on an individual-port basis for
additional security.
• Optional response string programmable for
every primary password defined by the user.
User-programmed response strings can be up
to 32 characters in length.
• Onboard clock so that the user can program
certain passwords as valid only during specific
times of the day (for example, night; evening).
CHAPTER 2: Introduction
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