ProductsProduct Communication and Layout

Product Communication and Layout

SmartLAN, I/O Bus & Wireless I/O Bus

Walker Technologies’ versatile products use a combination of SmartLAN, I/O Bus, Wireless I/O Bus to communicate in a system setting. This page explains walker’s unique product communication methods, as well as system structure and product layout.


The Walker Technologies network SmartLAN, was specifically designed for use with SAC operating systems in real-time process control applications. The powerful and flexible architecture of SmartLAN can be applied to any building layout, maximizing configuration and expansion options and system simplicity, while reducing component count and operating costs. This reduces system cost both at startup and during the service life of the control system.

SmartLAN networking capabilities are built into every Walker controller. Two or more controllers form a network using an inexpensive two conductor shielded cable. Priority based data transfer and inherent high electrical noise immunity of the IEEE RS485 standard provide unprecedented LAN performance. It is an interrupt driven, prioritized token passing protocol, providing true peer status to all connected SACs. SmartLAN prioritizes all information, guaranteeing instant response to alarms and operator requests even in heavily loaded networks. All network sections in a Walker system use SmartLAN, so any two panels anywhere in the system can communicate.


• 38K4 baud
• RS485 twisted shielded pair
• Each LAN 1 Km
• Up to 50 SAC's & nodes on the main
• Up to 2500 additional controllers on
  local LANs

• True peer protocol throughout the entire
• Instant response to urgent operator
• High throughput independent of network
• Seamless data transfer across main and
  local networks
• Programmable highway points
• Global system access from any
  connected SAC at any SmartLAN
  highway location
I/O Bus
I/O Bus is a two wire communications bus that allows connection of remote I/O modules directly to any of our MicroSAC products. I/O Bus is cost effective because it allows greater control application possibilities. Using the I/O Bus results in significant engineering, cabling and installation cost savings.

The I/O Bus communication link is a 2 wire shielded cable that also doubles as the power supply for low power devices, further reducing costs by eliminating the need for separate power supplies. Available modules include a line of RoomSTATs, a variety of I/O Bus expansion modules.

The allowable number of I/O modules added to a panel is dependent on the type of I/O modules and controller selected (typical applications: 32 I/O modules per WS1616, 24 I/O Bus modules per MicroSAC/ MiniSAC).

Take advantage of the I/O Bus features to decrease the total installed cost for most applications. Use I/O Bus and its modules to do the following:
• Reduce Hardware Costs
• Reduce Wiring Costs
• Reduce Installation Costs
• Reduce Engineering Time
• Easy expansion

Mesh Network
Wireless I/O Bus
Click here for more information on Wireless I/O Bus

Wireless I/O Bus products communicate using a ZigBee mesh network. This type of network allows data to automatically pass from node to node (device to device, i.e. thermostat, sensor etc…) wirelessly which allows these networks to cover large areas.

Another benefit of the ZigBee mesh network is that if a device loses its signal and can no longer transmit data through its current RF pathway, it will reroute its data to reach its destination through another RF pathway to reach its destination.

Each ZigBee Mesh network is capable of handling hundreds of nodes (devices). Walker Wireless is capable of running numerous mesh networks simultaneously, allowing for control of thousands of nodes (devices) in one system. The Walker Wireless mesh network solution applied in commercial buildings based on zone capacity and accuracy, is of a caliber unlike anything else in the HVAC industry.

• Full RF redundancy, with multiple data paths
• Self-configuring / Self-healing
• Distributed intelligence

For more information please contact

© 2012 Walker Technologies Corporation