Safety at Work has been available for over 10 years. Today, Tim and Helge talk about the various iterations of the "Consortium" Safety Monitor, developed by a group of companies that include Pepperl+Fuchs, Allen-Bradley Guardmaster, Siemens, and Schneider Electric to name only a few, and the major changes that have occurred over the years.

• - Safety Monitor "release 1.0"
• - Safety Monitor "release 2.0"
• - Safety Monitor "release 3.0"
• - PLC diagnostics

In the last few episodes, Tim and Helge started introducing Safety at Work, the safety technology that uses AS-Interface as its communication backbone. Starting this week, TechTalk will cover the various generations of Safety Monitors starting with the first unit frequently called "Consortium Monitor."

• - Why networked safety is advantageous
• - The "Consortium" Safety Monitor and its features and limitations
• - Sharing of safe data on AS-Interface

Using a safety-rated input module, any kind of safety device with dry contact or electronic safe output can connect to AS-Interface Safety at Work.  AS-Interface suppliers also offer safety equipment like e-stops and protective door switches with integrated safety electronics.

• - Safety dry-contact inputs
• - Safe electronic inputs
• - Safety devices with integrated AS-Interface safe electronics

Last week, Tim and Helge talked about the Safety at Work protocol and mentioned the Safety Monitor. In this episode, they discuss what the Safety Monitor does and why it is necessary.

• - What is a SafetyMonitor?
• - What is safety logic?
• - How many safety devices per network
• - Replacing a failed Safety Monitor (see www.sensing.net/asi)
• - Does every safety system need a SafetyMonitor?
• - SIMON+, the safety configuration software

Safety at Work is a powerful, yet simple safety technology for AS-Interface.  In this episode, Tim and Helge talk about how it is possible to process safe and non-safe information over the same network.

• - Safety sequence
• - Backward compatibility
• - Replacing a failed safety device (see www.sensing.net/asi)
• - Released-state data vs. safe-state data
• - Intelligent safety sequence substitution

AS-Interface is designed to be a cost-effective, highly distributed solution.  I/O blocks with as few as two inputs are available.  In this episode, Tim and Helge talk about the AS-Interface protocol explaining how I/O blocks and gateways communicate with each other.

• - Master call
• ----4-bit payload
• ----4 bits of outputs
• ------A/B addressing
• ------Specification 3.0 A/B addressing module with 4 outputs
• ----4-bit modules
• - Analog 8 in module
• - 2 input modules
• - Analog modules
• - Safety modules

AS-Interface is designed from the ground up to be noise resistant. The flat cable makes it easy to use even in wet applications.  Still, it is not uncommon for installers to make mistakes that can easily be avoided.

• - Differential signals and symmetry
• - Ground faults
• - Properly installing AS-Interface
• ----Separating data and power cables
• ----Routing along motor and VFD cables
• - Error counters (gateways and analyzer)
• - Shielded cables

AS-Interface is a topology-free network allowing the network cable to be routed in just about any shape desirable.  Repeaters, and in some cases terminators, allow the creation of very large networks -- 1000 m or more.

• - Segment length
• - Extending networks using repeaters
• - Can we build a ring?
• - AS-Interface in a Hurry -- Segments and Networks on YouTube 
• - Using an AS-Interface terminator

Many AS-Interface gateways on the market have some kind of LC-display.  In today’s TechTalk Tim and Helge explain why such displays are helpful during the engineering as well as during the operating phase.

• - Identifying missing slaves
• - Detecting unknown slaves on the network
• - Earth fault and peripheral fault
• - Other functions accessible via the display and function keys
• - Accessing the AS-Interface counters
• - Set outputs, read inputs

Properly powering an AS-Interface gateway is import.  In this episode Tim and Helge cover various methods of applying power and explain advanced features offered by some modern AS-Interface gateway designs. 

• - Black and yellow terminals on advanced gateway
• - Considering voltage drop
• - Power redundancy
• - Advanced features of gateways
• ---- Duplicate address detection
• ---- Ground fault detection
• ---- Noise detection