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Access Control UL294/294B Regulations Explained

Access Control UL294

UL294 is the standard of safety for Access Control System units that all access control systems must meet. UL294B is a newer standard, specifically for the use of Power over Ethernet (PoE) components used within access control systems where PoE is the primary power source.

Access Control

Government and state regulations are moving towards requiring UL294 compliance. Comtrol’s RocketLinx ACS7106 is the first UL294B certified switch enabling confidence in deployment and integration within access control systems.

The ACS7106 switch features four 10/100BASE-TX PoE Plus ports for providing power and data to remote PDs (Powered Devices) such as access card readers and IP surveillance cameras, and two 10/100/1000BASE-TX uplink ports that assure maximum throughput for high bandwidth applications.


The official site for the UL Standards states that:


1.1 These requirements apply to the construction, performance, and operation of systems intended to regulate or control:

a)    Entry into a protected area or a restricted area or

b)    Access to or the use of a device(s) by electrical, electronic or mechanical means.

1.2 These requirements apply to computer equipment that, when used in conjunction with the main control, is necessary for proper operation of the access control system. This Standard does not apply to supplementary computer equipment that is not necessary for operation of the access control system if single opens, earth ground faults or wire-to-wire shorts on the circuit connection from the computer to the access control system does not inhibit intended operation.


1.1 This standard provides requirements for the evaluation of Power over Ethernet (PoE) power sources for access control systems and equipment. The power sources may be provided integral with the access control equipment or as a separate device supplying power. The equipment is intended to comply with Article 725.121, Power Sources for Class 2 and Class 3 Circuits, of the National Electrical Code, NFPA 70. Equipment covered by this standard provides a nominal source voltage of 48 or 53 V DC.

Access Control UL294

1.2 This standard applies to all connected equipment and interconnections necessary to ensure normal operation of the PoE powered control system.

1.3 PoE sources covered by this standard are not intended to be located in an outdoor environment.

1.4 The PoE source shall meet the applicable requirements of the Standard for Access Control System Units, UL 294. See 2.2.4 and 2.2.5.Outdoor Use Equipment; Sections 70 – 81 of UL 294 inclusive are not applicable.

These system standards apply to the construction, performance, and operation of systems intended to regulate controlled areas. These types of areas might include entry into a protected or restricted area or access to or the use of a device by electrical, electronic or mechanical means. By having a system with devices that are UL294 listed, you can avoid costly problems with contractors and inspectors.

For more information on the UL294 standard or the RocketLinx ACS7106 PoE switch, please contact [email protected] or 763.957.6000.

Process Automation Monitoring and Control with IO-Link


A leading oil product manufacturer chose to work with Comtrol on a variety of applications involving IO-Link. For Application 1, the company wanted to create greater visibility with their storage tank pressure and flow rates. Application 2 needed to track presence detection and flow rates to supervise oil feed into a bottling machine. Application 3 focused on label detection on conveyor lines.

Application 1:
The user desired to monitor their pressure and flow rates of oil being supplied to their holding tanks. They installed a Comtrol IO-Link Master DR-8-EIP inside a cabinet that could communicate with the IO-Link sensors. If the rates were too high, the operators would know remotely through their EtherNet/IP PLC. The Comtrol IO-Link Master also gave them greater sensor diagnostic and status information through its extensive web-interface.

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CNC Machines Adding Intelligence Through The Use of IO-Link and Comtrol’s Master

CNC Industrial Machinery,detail shots.

Various industries often stick with components that just get the job done. But for one machine builder, they have taken a more forward thinking approach. By implementing spindles that are IO-Link capable, it is giving their customers greater insight that can be very valuable. While CNC machines are already intelligent, IO-Link offers added intelligence.

These IO-Link spindles run a cutting tool on a CNC machine and are connected to a CNC controller using Comtrol’s DR-8-EIP IO-Link Master. They learned that it would be possible to use ISDU (Indexed Service Data Unit) messaging via IO-Link to read certain data worth monitoring. The machine builder wanted to read data from the spindle including circuit board temperature and vibration. The spindle would also provide collision detection and includes cycle counters for mechanical parts. Other standard, non IO-Link spindles often just perform as designed without giving much access to data or diagnostic information. But by using an IO-Link version, it allows them to offer a “smart machine” to end-users by utilizing this powerful technology and communicating this information to the controller using the Comtrol master.

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Comtrol Delivers Networking Reliability at Super Bowl LIVE

Comtrol Delivers Networking Reliability at Super Bowl LIVE

Last month, in preparation for Super Bowl LIVE, Comtrol Corporation’s Rocketlinx PoE Switches were selected by the City of Houston to manage the networking side of their cutting-edge surveillance system.

The system, installed by Houston-based security integrator Pref-Tech, deployed dozens of AXIS cameras and speakers, Louroe Electronics sound detection equipment, and Siklu radios to monitor entryways, stages, and entertainment areas throughout the more than 750,000 square foot plaza.

A combination of Comtrol’s Rocketlinx PoE Switches, SFP’s, and industrial power supplies were deployed at Discovery Green to manage all of these devices in the urban park. “Given the size of this event, it was extremely important that we deployed a reliable security network that could provide continuous coverage over a large outdoor area,” said Jack Hanagriff, from the City of Houston’s Office of Public Safety and Homeland Security.

Among the Comtrol products deployed was our Rocketlinx ES7510-XT, a managed, PoE Plus Fiber switch designed to meet the high power and advanced management needs of critical security applications.

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Comtrol’s RocketLinx Switch “the Edge of the Network” for Mcity

RocketLinx Switch

The University of Michigan, in partnership with the Michigan Department of Transportation, designed and built Mcity, a unique urban-suburban environment for testing connected and automated vehicles and systems.

Mcity sits on a 32-acre site on the University of Michigan’s North Campus, with more than 16 acres of roads and infrastructure. It includes approximately five lane-miles of roads with intersections, traffic signs and signals, sidewalks, benches, simulated buildings, street lights, and obstacles such as construction barriers. This environment allows the testing of new technologies, such as autonomous vehicles, in a safe, controlled, but otherwise real-world environment.RocketLinx Switch

At Mcity, each set of traffic signal devices in an intersection, on-ramp, rail crossing, crosswalk, etc. is connected to the facility’s traffic management network via a dedicated fiber link using Comtrol’s ES8510-XT switch. This network then consolidates each of those connections onto a high-speed backbone, which in turn connects to a state-of-the-art traffic control center, located near Mcity at the U-M Transportation Research Institute (UMTRI).


Automation Integrator uses Comtrol for Device Connectivity

DeviceMaster UP 2-port 2E

A leading integrator of factory automation and robotics solutions selected the Comtrol DeviceMaster UP 2-port 2E for a production line cell for forging spindles. In this application laser markers communicating via Ethernet TCP/IP were used to apply a serial number to the spindles. The commands were sent to the marker through a PLC running Profinet. Further down the process, the spindles are loaded into a dunnage box that is applied with a label that lists the part number, date/ time, and operator ID. This data is passed to an Ethernet TCP/IP label printer from a Profinet PLC through the DeviceMaster UP 2-port 2E.

DeviceMaster UP 2-port 2E

Comtrol’s DeviceMaster UP 2-port 2E was the perfect solution because it can connect multiple TCP/IP Ethernet interface devices to an Industrial Ethernet protocol. In addition to Profinet, these devices can also connect to Ethernet/IP and Modbus TCP controllers.

The DeviceMaster UP provides the following communication modes:

  • EtherNet/IP™ to Serial or Ethernet TCP/IP
  • PROFINET IO to Serial or Ethernet TCP/IP
  • Modbus/TCP to Serial or Ethernet TCP/IP
  • Modbus/TCP to Modbus/RTU
  • Modbus/RTU Device (Auto Locate and Auto Route)
  • TCP/IP Socket Communication

For more information, please contact [email protected]

Paint Spraying Operation Integrates IO-Link


A furniture manufacturer was in need of a time and money saving solution. This company needed something that could identify the size of sections of furniture on the paint spraying line and thus reduce over-spraying and wasting paint. Leuze’s CML720i light curtains that were IO-Link enabled were chosen to accurately measure piece dimensions. They also needed an IO-Link master block that could handle the power requirements and effectively communicate with the PLC.

The CML720i light curtains are positioned at the entrance of a paint powder coating machine which tell the automated paint guns when to spray and when to turn off, based on the size of the piece moving through. Before this solution, spray guns would turn on well before a piece arrived and remained on well after, which over time wastes a large amount of paint. They also wanted to avoid spraying the hooks connected to the conveyor system which guided the pieces through the painting machine. All of this information is communicated to a PLC running on EtherNet/IP via the Comtrol IO-Link master 8-EIP.

By using Leuze’s CML720i light curtains that are IO-Link version 1.1 devices, they are able to save parameters set for the CML720i light curtains right in the Comtrol IO-Link master by using an IO-Link feature called Data Storage. This allows the customer to easily replace a CML720i light curtain and automatically upload the previously saved settings to the newly connected curtain. This eliminates the need to configure the device from the default state.

Comtrol was able to meet the needs of this application in a number of ways. The IO-Link Master 8-EIP supports high power current support, including 1.6 amps on port #1, which is required to operate the large CML720i light curtains. The IO-Link Master also provides power overload protection. If a device is connected that is attempting to pull more power than can be provided, the IO-Link Master will shut down that port once a certain threshold is exceeded. When the power draw subsides, the port will re-activate. In addition, the powerful web-interface provides the customer will multiple benefits that most master blocks do not.

For example, the web-interface allows the user to:

  • Save IODD files in a library
  • Utilize data storage
  • Change the parameters of a device right in the web-page
  • Use device validation to allow a specific device to work on a specified port
  • Configure ports to operate as an IO-Link port, Digital Input or Digital Output
  • Look at PLC diagnostics

For more information, please contact Brandon Roy.

PRODUCT RELEASE: DeviceMaster ® RTS 4-Port DB9 2E

DM UP-RTS 4P DB9 2E Product Announcements Blog Post




DeviceMaster ® RTS 4-Port DB9 2E

The DeviceMaster RTS 4P2E is the 4-port model of Comtrol’s popular line of industrially-focused DIN-rail mount serial device servers.  Packaged in a compact, rugged housing, the RTS 4P2E model provides four serial ports via standard DB9 male connectors with the additional benefit of a two-port Ethernet switch to support a variety of network installations.  Featuring the same Linux and Windows certified drivers, SSL/SSH security, and intuitive configuration as the rest of the industry-leading DeviceMaster family, the small-form factor RTS 4P2E is the perfect serial expansion solution for panel builders, cabinet installations or any application where performance demands are high but space is at a premium.


  • Wide DC input voltage range (5-30 volts)
  • Redundant power input for fail-safe powerDeviceMaster RTS 4-Port DB9 2E
  • RS-232/422/485 software selectable interfaces
  • DB9 male serial connectors
  • PortVision DX
  • Screw terminal power connector
  • Dual Ethernet ports for daisy-chaining devices
  • 25KV surge protection for serial ports
  • Features DIN rail mounting
  • Wide operating temperature range (-40º to 75º C)
  • NEMA TS2 certified
  • SSL & SSH management, SSL serial data stream encryption
  • Wide input power range
  • IPv6 support
  • Real-time email event notification


Product Overview

The DeviceMaster RTS 4-Port DB9 2E serial device server can be used to network-enable two serial devices on any Ethernet network and is ideal for applications in: traffic and transportation, power utility, industrial automation, material handling and any project that requires serial-to-Ethernet communication with DIN rail-based equipment installations.
For more information or to request an evaluation unit, contact [email protected] or 763.957.6000

Mining Application Using IO-Link Master and PC

A North American mining systems integrator implemented a solution for a mining application company seeking a better way to identify particle size and increase awareness of jams on their mineral fragmentation conveyor line.

Mining Application

Mining Application Using IO-Link Master

Comtrol’s IO-Link Master 4-EIP, with the IO-Link laser distance sensor connected, helped them achieve both of these tasks. The main reasons they decided to use Comtrol’s IO-Link master were:

  • Comtrol’s master is able to work directly with a PC, no PLC required
  • Other IO-Link master solutions rely on a PLC to use and set up the master, which was not desired for this mining application
  • The ease of set-up, powerful web interface and Modbus TCP support were other determining factors.

The end-user was using a vision system for analyzing mineral fragmentation on a conveyor line. The mineral would be broken down and sent along the line where the vision system would ensure the particle size was correct.

However, problems exist with picking up accurate readings when the bed depth, or amount of mineral on the line, is great. Working with Comtrol’s IO-Link Master that is used to connect the IO-Link distance sensor has helped the company increase their accuracy with reading the bed depth. The laser distance sensor is also used to pick up the distance to the top layer of mineral going down the line which helps normalize the data along with the vision system. This improves accuracy in analyzing mineral particle sizes as the line moves along.

To continue reading the story, click here.

To learn more about Comtrol’s IO-Link Master, please contact [email protected].


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