and more, the main impetus behind putting safety on an industrial network is to
increase productivity. Along with the primary goal of protecting the people
working in a manufacturing operation, the level of diagnostics available with
networking can have a direct impact on reducing downtime. The better the
diagnostics, the faster a user can troubleshoot a system to get it up and
running again which, in turn, increases productivity and makes for a safer
With the move to networked safety systems, especially on
Industrial Ethernet, there has been an increase in the number of devices
available for safety networks such as failsafe motor starters and drives. In
the past, safety devices were hardwired into the system and provided a minimal
level of diagnostics through the network.†
E-stops, for example, were either on or off, with no more detailed
diagnostic information available.
But now with safety networks, a
large amount of safety data can be passed over the network in a failsafe way.
This facilitates designing complex safety systems and architectures that are
easy to implement.
Safety System Trends
|This topic will be covered in a panel discussion featuring
representatives from Siemens, Rockwell Automation and Mitsubishi
Electric Automation's CC-Link. Follow this link to access the live event
on April 21, 2011 or, after that date, view the archived version: |
major trend in safety systems hardware and software is the combination of
operation, machine and motion control in one controller. Many systems
in the past had separate controllers for motion and safety. But increasingly,
all of these functions are available in a single controller on one network.
It's also becoming easier to
integrate use of standard and safety devices in the same system, and on the
same network. For major suppliers such as Siemens, motor starters and failsafe
drives are integrated on the company's distributed I/O network. For customers
implementing systems, the process of adding safety devices is similar to adding
an I/O drop at a location. Adding either standard or failsafe devices to the
network is a seamless process within the same I/O drop.
Another safety technology area
picking up speed is wireless safety. Especially in warehouses or distribution
centers where material handling applications such as gantry systems are used,
it is difficult and expensive to do all of the wiring required to integrate a
safety system. Wireless is the perfect fit for applications where there is a
strong desire to limit the number of wires. Wireless systems are easier and
faster to implement, and also use a minimal amount of floor and cabinet space.
An additional innovation with
wireless safety is the use of mobile safety panels, which alleviates the issues
of HMI panel placement since E-stops can be implemented on the mobile panels.
With a static HMI panel built into the machine, the operator often needed to
physically go to the HMI to determine the problem. With the mobile safety panel
operating over a wireless connection in the operator's hands, he can walk
around the machine and view diagnostic screens, using switching zone controls
to view different parts of the process. Another benefit to the mobile safety
panel is the ability to control multiple machines with safety.