Sealevel Technology Application: Enter the ArenaMonitoring

March 16, 2011

March is an exciting time for college basketball fans: the regular season is winding down, conference tournament play is underway, and tournament bracketology becomes a science and a passion. And arguably, no basketball fans are more passionate than University of Kentucky Wildcat fans.

From seventh grade to my sophomore year of college, I worked part-time for Lexington Center — the corporation that manages and operates historic Rupp Arena, home of the UK Wildcats. Over the years, my tasks included popping massive amounts of popcorn in preparation for events, working concession stands, vending, managing vending commissaries, and providing refreshments for the press room. I have great memories of those early, formative work experiences. The management team willingly intrusted a group of 13 year-olds with what I now see as a great deal of responsibility, and we rose to the tasks. A side benefit was being part of the excitement and energy of Rupp Area during a UK basketball game, although it was often behind the scenes (or more accurately under the seats.)

An arena is a massive facility and is the venue of choice for this example application of Sealevel technology.


A control booth on one end of an arena must provide control and obtain status from various equipment on the far side of the arena. Due to the physical separation, the control booth and the equipment panel are on different power sources in the arena. The equipment is wired from a shared panel and may include:

  • Scoreboard
  • Digital signage
  • RF power sensing/control
  • Audio/Video feed switching

The equipment panel must also provide status and control, localized at the panel, to allow for maintenance, override, etc. It is also desirable for basic equipment interaction to be automated at the equipment panel to maximize responsiveness and minimize loading on the control booth. Examples may include automated loops on the digital signage, or monitoring and fail-over to redundant systems.


The large distance from the control booth to the equipment panel and separate power feeds pose the following challenges:

  • Signal integrity
  • Size of the cable bundle (need to reduce wiring run and maintenance)
  • Possibility of significant potential difference between the control booth ground and the equipment panel ground

The desire for status and control at the equipment panel as well as automated equipment control at the panel poses additional challenges:

  • Equipment panel human machine interface (HMI) should be easy to understand and control
  • The equipment panel must include sufficient processing power to status and control equipment
  • Status and response application development for automation should be standard, portable, and upgradeable

Example Solution
For this scenario, Sealevel isolated RS-485 hardware and the SeaPAC R9-8.4 ARM9-based touchscreen computer may be used to provide an end-to-end control solution for this scenario.

Enter the Arena: Sealevel Technology Example

Block Diagram
In the example block diagram, the Host Controller (PC) contains a Sealevel 7108 low-profile PCI RS-232/RS-422/RS-485 isolated serial interface card in RS-485 mode. The RS-485 electrical interface standard allows cable lengths up to 4000 feet. The differential driver/receiver pair provides noise immunity, and Sealevel hardware provides automatic RS-485 hardware enable to eliminate the risk of bus contention on the shared differential signal pair. The Modbus RTU protocol may be used to communicate across a three-wire run (data +, data –, and GND) to the equipment panel.

The equipment panel contains a SeaPAC R9-8.4 (P/N S91100-8R) panel-mount touchscreen computer. This embedded ARM9-based solution provides dual isolated RS-485 ports: one for the Host Controller interface and the other to control the various equipment required. The SeaPAC R9-8.4 also includes open collector outputs, which may be used to drive a status light pole. For additional I/O, the SeaPAC R9-8.4 allows for expansion – either via RS-485 expansion port or via two USB host ports to Sealevel SeaI/O modules. This expansion allows analog I/O, digital I/O, isolated I/O, and relay outputs to be added to the SeaPAC R9-8.4. A 10/100 Ethernet port is also available to connect to a local network or wireless bridge.

For rapid application development, the SeaPAC R9-8.4 includes Windows CE 6.0 BSP binary and low-level drivers for system I/O as well as the Sealevel Talos I/O framework, which offers a high object-oriented .NET Compact Framework (CF) device interface. The interface provides an I/O point abstraction layer with built-in I/O functions like gain control and debouncing. The SeaPAC R9-8.4 manual provides a software QuickStart Guide to help you get up and developing applications in minutes. The application provides the customized automation required for the scenario and provides intelligent I/O control to offload the Host Controller. The SeaPAC R9-8.4 touchscreen may be used to display status and obtain input from an operator directly from the panel.

This arena application scenario highlights just some of the many ways Sealevel products may be used to solve distributed and intelligent I/O needs. From isolated RS-485 cards to embedded processing solutions like the SeaPAC R9-8.4 touchscreen computer, Sealevel is committed to providing solutions and supporting your application. And just as March Madness brings out the passion in college basketball fans, the challenge of developing a custom solution with our customer brings out the best in Sealevel engineering.