PLC controllers provide reliability, lower risk
- By Tony V. Capelli
- Jun 01, 2015
A large corrections campus, encompassing more than 30 buildings in
the southeast United States, houses approximately 5,000 inmates
with separate jail facilities for men and women who are awaiting
sentencing, serving sentenced jail time and are in maximum security.
Correctional institutions require extremely reliable and robust
security systems to ensure the safety and security of both personnel and inmates.
The linear design of the jails at this facility requires inmates to be moved between
locations—including cell blocks, meal areas, recreation and visitation—individually,
in small groups or via mass movement.
The correctional facility’s 20-year-old door control system was made up of outdated
PLC controls and old relays with old wiring to control secure doors and
mantraps. A massive upgrade was required to enhance and provide state-of-the-art
security technology using high-quality, reliable door control systems. The unique
challenge was to maintain maximum security during the technology system upgrade.
Additionally, new maintenance policies and procedures needed to be implemented
to sustain security and guarantee stability.
Over the past two years, Dortronics has been working with Next Level Security
Systems (NLSS), which has been engineering and standardizing Dortronics 4700
Series PLC controllers for use across its base of correctional facility customers. In
tackling the project, NLSS partnered with systems integrator American Security
Group (ASG) of Vista, Calif., who is deploying the security logic controls and the
NLSS Gateway product as part of a total technology update across the approximately
30 buildings that make up the correctional facility.
After considering risk-avoidance, the team chose solutions that would ensure
the highest level of security. The scope of the entire project calls for 4,900 PLC
controllers to be installed to control more than 840 doors and 85 mantrap controls.
The implementation is being conducted in stages and is on-going with completion
of the project expected later this year.
“One thing was certain, we didn’t want to take any chances that may compromise
security at a corrections facility,” said Bill Jacobs, president of NLSS, who
is managing this project. “Mantraps are critical portals where controlled access
can mean life or death, and the 4700 series PLC mantrap controllers have proven
themselves. We’ve had no downtime at all.”
ASG has finished installation for two of the several systems scheduled for installation,
the first of which required securing more than 30 doors, and about a
dozen were mantraps. Gateway is used to control cell doors, with a Dortronics
mantrap controls incorporated to insure compliance with regard to interlocks. The
second system consisted of fewer total doors, but almost all of them were interlocked.
“Dortronics’ controllers have been integral to ensuring compliance with regard
to the correctional institution’s desire to maintain the highest level of security for
interlocked doors,” continued Jacobs.
The correctional facility’s previous system was, as Anthony Sparks, general
manager for ASG calls it, “a hodgepodge of mismatched PLC controllers,” which
fell far short of the state-of-the-art technology currently available. The disrepair
of the system led to the decision to upgrade with the goal of standardizing across
“The corrections campus had an aging system that was antiquated in many
ways, and they were unable to get adequate service,” Sparks said. “Many of the
installed components were either no longer manufactured or supported, or the
manufacturers were no longer in business.”
By contrast, Sparks says Dortronics has been responsive and helped ASG design
a solution that met the facility’s requirement to have a spare controller on-site
that could be easily swapped if necessary. Because every building on campus is different,
each system installation requires the controllers to be custom programmed,
which presented potential service issues.
Working closely with Dortronics engineers, ASG devised a set of standards that
could be implemented in the event of a component failure, which involve next-day
turnaround for new PLC controllers that are pre-programmed for each building.
“This is a custom job, and Dortronics turned around the designs very rapidly,
which was impressive—especially because in many cases, the design could
change almost on an hourly basis,” Sparks said. “In addition, their ability to provide
spares that are pre-programmed for specific building virtually overnight is an
Another requirement for the new system was switchover capability that would
allow the facility to alternate between new browser-based system control and traditional
analog graphic display panel control as needed or desired. The combination
of NLSS and Dortronics technologies allows on-site security staff to control
the system locally using either method, while also allowing door control to be
transferred to an off-site location via a browser in the event of an emergency.
“In the unlikely event of a riot or takeover, remote control of the system can
disable local door controls, preventing unauthorized individuals from controlling
doors on-site,” Sparks said. “This also ensures that at either software or analog
control, mantraps and interlocks are able to function as intended.”
Since implementing the new systems, the correctional facility has seen a number
of benefits, most notably increased safety and security.
“The immediate ROI is that security personnel know the mantraps
operate in the manner they were designed to operate. They
also know that there is no security risk based upon how the system
protects the various areas from each other,” Sparks concluded.
This article originally appeared in the June 2015 issue of Security Today.
Tony V. Capelli is a freelance writer based in New York.