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Active Ethernet I/O A New Solution for Data Acquistion

Supplier: Paqworks by Madison Technologies
10 July, 2007

Active Ethernet I/O is a new way for PC-based data acquisition & control applications to transmit real-time I/O data over an open network. Active Ethernet I/O is designed for Ethernet, and supports Modbus/TCP and SNMP protocols for use in both industrial automation and IT environments.

Active Ethernet I/O

The Active Ethernet I/O concept adds intelligence to the Ethernet I/O
server, allowing it to operate autonomously without a controller. With
built-in control logic, the I/O server can immediately and proactively
report changes in sensor status to a network host. The host no longer
has to go through the steps of polling for sensor status, waiting for a
response, and checking to see if there has been a change. The host can
simply wait to receive I/O status reports from the Active Ethernet I/O
server.

As the number of monitoring points grows, the benefit of the Active
Ethernet I/O approach becomes more apparent. Instead of overloading
the network and CPU with requests to multiple I/O points, the host can
simply wait for automatic reports from any I/O server, anywhere on
the network. The drastic reduction in network traffic and the greater
immediacy of proactive transmission finally makes it possible to
obtain real-time I/O data.

With this architecture, programs no longer need to be painfully complex to monitor a great number of I/O points. Furthermore, this architecture treats the I/O server as an independent, modular entity that allows the system to be easily modified or expanded, the way Ethernet was originally designed.
How is this accomplished? A simple logic engine on the Active
Ethernet I/O server monitors each attached sensor device.

The logic engine also checks to see if user-specified conditions have been met, such as whether a switch has been turned on, a current source has
exceeded 10 mA, or a counter value has reached 30. If a condition has
been met, the Active Ethernet I/O server immediately transmits a
report to one or more network hosts. This approach allows network
hosts to receive critical I/O data up to 20 times faster than with
traditional Ethernet I/O, within 50 ms as compared to 1 sec.

The I/O reports are designed for Ethernet and do not require special
programming or protocol conversion. TCP/UDP text messages, e-mail
notification, and SNMP trap are all supported. Active Ethernet I/O
servers can also function as traditional I/O servers, with support for
host polling by Modbus/TCP or SNMP.
Users of PC-based remote or distributed monitoring systems obtain the
following benefits:
* Critical I/O data is received in real-time with time stamp and
will not be lost due to polling intervals or network lag.
* Complex coding and slow response times are eliminated,
allowing the host computer to operate far more efficiently.
* IP network traffic between host and remote I/O servers is
significantly reduced.

For most applications, sensors are not only monitored remotely, they
are tied to local events. For example, in an underground tunnel,
emergency lights and alarms may be activated when a sensor detects a
rise in water level. Local systems are preferable for this type of
control, since remote systems are more susceptible to network lag or
outages.

Traditional “Passive” Ethernet I/O
Traditional Ethernet I/O servers cannot operate without instruction
from a host. Even simple switch control must be handled remotely by
the host, which means that additional programming is required and an
immediate response time cannot be guaranteed. Local control can only
be implemented by installing a local PC, a PLC with an Ethernet
module, or a separate proprietary system dedicated to specific
applications. None of these options are easily integrated into remote
monitoring systems, and all require a significant investment in time
and money.

Active Ethernet I/O

The logic engine on an Active Ethernet I/O server can respond
immediately to I/O events not only by sending a report to network
hosts, but also by sending simple commands to attached devices such
as buzzers or LEDs. This makes local alarm control possible without
an additional controller or PC.
This capability provides the following benefits:
* The Active Ethernet I/O server can provide simple control of
attached I/O devices without requiring a local host computer.
* Users can set rules for alarm activation based on sensor status.
* Since sensor data is locally monitored and analyzed by the
Active Ethernet I/O server, data is transmitted only when
user-specified conditions are met, making programming easier.
* Users can automatically receive reports of I/O events by e-mail.

Traditionally, experienced programmers were needed when setting up
a monitoring and control system for multiple I/O points. Complex,
customized code had to be written for PCs or PLCs, requiring an
extensive knowledge of ladder logic or C-language.

By contrast, one of the biggest advantages of Active Ethernet I/O is
how easy it is for users to manage how I/O events are controlled and
reported. By relying on the use of simple, intuitive rules, the control
logic can be configured in minutes without special training.

Since Active Ethernet I/O is designed specifically around Ethernet’s
strengths, it is easily implemented into existing IT systems. I/O events
are reported using protocols and formats familiar to any IT engineer,
and Windows and Linux APIs are available for the most popular
programming languages. Configuration is designed to be completed in
a few minutes, with little or no training and no programming. Remote
and distributed monitoring applications can be developed for a fraction of the cost and time required for traditional Ethernet I/O solutions.

Furthermore, many new applications are now possible.
Ethernet continues transform the industrial automation landscape with
its performance and versatility. With Active Ethernet I/O, a new
generation in IP-based data acquisition has arrived that finally
harnesses the strengths of modern network technology.

For further information please contact Paqworks to discuss your application.