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The core
of the Vsystem architecture,
Vaccess is a user-extendable, real-time, in-memory database and
library of access routines. Vaccess holds and
transmits data and functions as an event-driven bus, providing notification
of change upon request.
Vaccess maintains a responsive, secure,
memory-resident data description of your facility. From ASCII text files, a
GUI or by software, Vsystem generates a real-time
database configured for your application. You can divide the database into
many databases distributed among the computers of the system. Security can be
controlled per database or per channel. In a distributed, networked
environment, although a database resides on only one computer, all other
computers in the network have access to that single copy. Optionally, events
generated from that database update remote applications with significant
changes, ensuring efficient use of computing resources.
You can construct systems
from small, easily defined, tested modules. In essence, Vsystem
breaks complexity down into manageable pieces.
Features of Vaccess:
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Speed, manageability, security, and scalability
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High performance and memory resident
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Channel types: binary with text support, integer (8-, 16-, and 32-bit;
each either signed or unsigned), single-precision floating-point,
double-precision floating-point, string (232 characters), and time
(resolution 1 ns)
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All channels optionally time stamped
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Numeric channels can be arrays up to 232 bytes
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Array channels can be circular buffers with each value optionally time
stamped
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Each database can have up to 65,535 channels
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Up to 65,535 databases in a system, with any number on each computer
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Alarming with delayed alarms and with reference alarms
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Full programming
interface
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Event-driven change notification on all fields
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Dynamic memory management
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User-defined conversion routines with parameters for non-linear
conversion. User-defined conversion routines can be programmed or written as
a script equation.
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Conversion routines can do gets and puts
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Multiple conversion routines per channel, each with its own conversion
parameters
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User-written I/O routines
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99% of fields are dynamically changeable
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Channels can be added dynamically to a running system
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All releases intercommunicate - no need to upgrade your old system
when a new system is added
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256 alarm priorities
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Database, channel, and field security
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Database checkpoint manager to ensure that disk copy is current in
case of failure
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Application area and subarea fields supported for larger applications
Updated Jan
5, 2010
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