Optical Turnstiles for Safety and Security


Optical turnstiles were invented in the 1980s when more of security was needed for beautiful and expansive building entrances. Prior to this during peak periods there were hundreds of employees, visitors, and service providers coming and going, making it difficult to determine who was entering the space.  Buildings needed for tenants and visitors:

A pleasant experience while providing safe, secure, smooth, and orderly flow of personnel into and out of the building.

A pathway for visitors and exceptions such as disabled or baggage-laden persons.

Secured and alarmed doors beyond the turnstiles, providing safe yet secure egress.

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Turnstiles became a force-multiplier for building concierges and security officers who in the past may have been intimidated by a hard-charging visitor. Maybe someone claimed they’d misplaced their security credential, or claimed they were late for a meeting in the building. Maybe it was an ex-employee trying to use an old credential to get back to his office, or an ex-spouse or boyfriend trying to ride someone’s coattails in. The closed barrier of an optical turnstile helps attendants address the situation in a professional and secure manner.

Since the COVID threat emerged many building managers needed orderly and effective temperature/health screening at all entry points. Since a turnstile’s role is to allow only those persons properly vetted to proceed, they became the best place to incorporate screening equipment .

In a safety environment turnstiles allow screeners to work remotely out of harm’s way. DSI turnstiles and anti-tailgating systems have for example been used with temperature screening equipment (For COVID-19), PPE (such as facemask and hard hat) detection, electrostatic discharge equipment, and more conventional security screening equipment such as metal and radioactive material detectors.

Are employees and visitors socially distanced as they use your turnstiles? Where turnstile lanes are closely spaced, DSI’s new sturdy acrylic Separation Shields may be the answer. These stable and rugged barriers are easily installed with turnstiles (regardless of brand), low walls, or countertops.

Denning Electronics focuses upon a few key market-leading manufacturers, and DSI has been a cornerstone of our firm since the 1990s. While DSI has systems suited for high volume high security facilities they also have gear suited for public buildings, banks, data centers, industrial sites, and sports venues where the new norm is to safety-screen all who enter. We’ve recently supplied equipment for corporate headquarters, food processers, manufacturing and distribution facilities, and government agencies.

DSI turnstiles are compatible with most card and biometric access control manufacturers and elevator destination dispatch systems. We are qualified and confident since we’ve been deployed in some of the most secure facilities in the world. We’re prepared to share our knowledge with you and your clients in confidence.

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Vigitron makes networks better


Vigitron solves Ethernet networking challenges for security and communication systems. The big four are:

It’s nearly impossible or simply too expensive to get Ethernet cabling and power to where cameras, intercoms, access control readers, or SIP phones are needed.

Cable distance is too long for Cat 5/6 Ethernet, and there is no secure place for an IDF.

Our outdoor security devices (cameras, intercoms, sensors, lights) aren’t reliably powering-up or they fail when heaters or illuminators turn on.

There’s no convenient way to health monitor all of our security system components. Often the first we hear of a failure is when we most needed it!

Vigitron has long provided a compliment of physical tools to test edge devices and monitor networks. 2020 marked the beginning of NetObserver, the first in a family of software tool designed to provide real time network monitoring.

NetObserver is a next generation health monitoring Windows™ based software capable of receiving status messages from up to 240,000 ports using TCP, UCP, Syslog and SNMP communications. NetObserver recognizes network connected devices by means of Onvif, UPnP and also allows for manual entry. 

Why health monitoring? Large and small security systems with IP CCTV cameras, intercoms, and access control devices must be dependable. Unlike IP phones or other common devices powered by PoE, high power and high bandwidth PoE security devices often have different component states. Outdoor day/night cameras and LED lighting have power requirements that vary by day and by season, so a PoE switch with an inadequate power budget is prone to fail. NetObserver’s GUI with email notification traces the problem, making it easier to quickly respond.

A built-in mapping feature accounting for both IP-enabled network and edge devices ensures manageability, while custom messaging pinpoints trouble.

The Application Programming Interface used to manage the database is Microsoft’s SQL Server Compact 4.0, which is automatically included in the NetObserver installer.

In 2020 Vigitron introduced PoE Ethernet over untwisted conductors, and in 2021 is introducing more switches and components aimed at the industrial market, hardened smart switches with ring topology ensuring high reliability, and more tools to ensure top performance from your security components and network.

Do you have a project? Whether you’re an end user, integrator, contractor, or security dealer, we’re here to tackle your network issues.

Supply Chain Security During a pandemic – Southwest Microwave


When COVID-19 hit the international supply chain was severely disrupted. Some material movement ground to a halt as product demand stalled and factories closed, while there was immense pressure to move essential commodities (Fast Moving Consumer Goods – FMCG) and healthcare products. We learned from some clients that as warehouses strained to reorganize inventory, material was left on trailers or on docks in containers where they were more vulnerable to theft. This article in Corporate Compliance Insights highlights some previously unseen supply chain issues.

Southwest sensors have been deployed to protect supply chain assets for decades. Clients include auto, truck, RV and golf cart manufacturers, tire manufacturers, pharma logistics facilities, durable goods facilities, and clothing distribution.

The key to a successful deployment for distribution operations is understanding what is at risk and when/where are goods most vulnerable. There is no substitute for starting with a physical security risk assessment (RA) followed by a vulnerability assessment (see January 15, 2020 post “Is There More to Perimeter Security . . .).

While most Southwest deployments are fixed, we provide excellent portable rapid deployment sensors for products that are moved about from week to week or month to month.

Does it make sense to have a conversation about protecting your company’s supply chain?


Denning Electronics is proud to announce that we now represent SECO-LARM, manufacturers of innovative security and surveillance equipment for commercial, industrial, and institutional facilities.

With 40 years of R & D experience and over 200 domestic and international patents, SECO-LARM stands out as an innovator. One of the greatest benefits of buying from SECO-LARM is simply the wide breadth of well-designed products.

Distributors and dealers and their clients in nearly 100 countries worldwide know they can count on SECO-LARM access control, physical security, CCTV, A/V, and wireless components and solutions. With such a broad line of CCTV cameras, electromagnetic locks, door strikes, card readers, keypads, intercoms, exit devices, RF wireless, and sensors, you’ll rarely need to go elsewhere to complete your projects on-time and under-budget.

Denning is eager to show you SECO-LARM products. Please call or email Steve Vivacue or Ken Wippich to schedule an appointment.

When IP video and intercom systems stop working

We’re here to ensure dealers and integrators profitably increase sales and lower the cost of the systems they support. We are a resource not only for our current lines, but we also help with products we haven’t worked with for a decade or more and some we’ve never directly represented.

We are currently helping integrators and their clients who experience cameras, video clips, and intercoms mysteriously disappearing on their IP systems and recorders. Vigitron tools get to the root of the problem after it’s determined that the camera/recorder/intercom has been programmed properly and is otherwise in good working order.

Vigitron’s unique and economical diagnostic tools are purpose-built for security integrators. They may be used to evaluate and test cabling and networks before they are commissioned, and they track down problems caused by bad network wiring, insufficient PoE, or bandwidth-limited networks. Please contact us for a test drive of the NeTester/NetStat and NetObserver or one of Vigitron’s other test products.

Denning Electronics and COVID-19

Denning Electronics has protocols in place to contain the spread of Coronavirus. We’re engaging via email, phone, and Teams/Zoom/other conference services, and we’re making site visits following local protocols.

Some manufacturers are following stricter local or corporate guidelines, and/or have found it more effective for employees to continue to working home. We are prepared to arrange virtual, in-person, or hybrid meetings that work for you.

These are some of our products that are being implemented in response to the pandemic:

DSI – turnstiles and anti-tailgating systems providing orderly queues into and out of buildings and processing facilities.

Southwest Microwave – protecting manufacturing and supply chain facilities.

Vigitron – providing connectivity for screening and immunization portals.

Overly – Stainless steel doors.

Osprey – Chemical resistant FRP doors.

Denning Electronics has been solving tough critical communications, intrusion detection, IP CCTV, access control, and door (including ballistic, blast, and acoustic barrier) challenges for the past 37 years.   If you are a protection system manufacturer in need of professional representation or if you are a security system user, integrator, architect or engineer in the Midwest with a problem to solve, please contact us. We have a network of engineers, technicians, manufacturers, peers, distributors, and dealers that will succeed where others have failed.

DSI for Throughput – Custom Solutions

DSI relentlessly focuses upon reliability, security, and throughput. This video taken at ISC West in 2018 shows throughput for DSI’s 831 series barrier optical turnstile:

DSI 831 at ISC West

This is throughput for the 880 series turnstiles as demonstrated at ISC West in 2018:

DSI 880 at ISC West

Are you working with a tight space? If you have a tailgating problem, it might make sense to have a conversation with us. No pressure, no cost.

Most barrier optical turnstile projects have a custom element. Do you need extra heavy duty service? Do you need to match the lobby decor?

For more information or a site visit, please contact Denning or visit DSI’s web site.

DSI website

Is There More to Perimeter Security than Video? – Part 2

It’s been nearly three years since we posted comparing sensor-based perimeter security to video-based outdoor intrusion detection systems. Has anything changed?

The security market is video-centric. We get it – CCTV is a good tool, and it keeps getting better. Every year hundreds of firms plow millions of dollars into CCTV R & D, and millions more are invested in mobile platforms such as drones and artificial intelligence and its integration with security systems. Video is arguably the most visceral security tool available, exceeding even “eyes on” assessment since systems are capable of collecting and displaying information we cannot see (think thermal and IR imaging of the invisible).

If your system has been designed and installed right and everything’s working properly, video addresses what happened and when it happened. With improved internet connectivity you now may have the means to see what’s happening now, and remotely intervene when a crime is taking place. Using high tech tools under ideal circumstances you may even identify a perpetrator.

Denning has sold over $200 million of physical security, communications, and network products* over the past four decades, and we’ve learned crime often doesn’t happen under ideal circumstances. We appreciate layered systems using tools such as CCTV, intrusion detection, communications, access control, and screening that together mitigate an enterprise’s vulnerabilities.

There’s no substitute for for starting with a physical security risk assessment (RA) followed by a vulnerability assessment (VA). The RA outlines the threats, while a VA shows under what circumstances assets are at risk. The VA will also outline and perhaps quantify the potential impact.


Some situations add Deter, Deny, Assess, Communicate, and Intervene to address a particular vulnerability. We do so understanding ASIS International ESRM (Enterprise Security Risk Management) models and tools.

If you’ve determined it’s people you’re trying to find, consider the environment. Even the best lighted perimeters with low light/no light video technologies may be compromised if there’s blowing sand or snow, and/or fog. At a minimum you should be considering a layered “defense in depth” approach, with physical and electronic systems providing enhanced protection for the times when conditions are bad.

Testing cameras in an ice fog with air temperatures of -2 F.

As outside reps for leading industry manufacturers, we have field experience with scores of sensors and systems.

It is with this insight that we repeat: many of our clients once felt that video was their best line of outdoor perimeter defense. Video was chosen to tell them how something happened, and who did it. It took one incident to tell them they need more than video alone can provide.

*Denning is a manufacturer’s middleman that sells to resellers, so these sales estimates reflect wholesale equipment costs less accessory components and installation.

Dealers and integrators: ask us about project registration!

If you’re an integrator that’s helped designed a project around Denning manufacturers, we should be talking.

We represent manufacturers that appreciate the commitment it takes to get larger infrastructure, transportation, institutional, and enterprise projects of the ground. If you’ve invested time there may be a registration reward program for you.

We at Denning have provided surveillance and detection systems for bridges (though as far as we know, not for this particular bridge just south of Ping Tom Park in Chicago). Southwest Microwave is being used to detect ships and prevent bridges from closing on them as move along the Illinois river.