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  • Wireless Temperature Monitoring System Topology Considerations

    Smart decisions during the evaluation process can help simplify the sensor network layout.


    In this ongoing series centered around NYC Hospital Queens’ experience in selecting and installing a Wireless Temperature Monitoring (WTM) system to track medications and blood in hospital refrigerators (Link to Article) several factors as to the placement of WTM devices to support 174 refrigerators, freezers, and other critical areas in a hospital that is comprised of four main buildings, some built in the 1950s needed to be taken into account.


    As was noted in a previous piece, the WTM system chosen at NYC Hospital Queens uses  wireless receivers located above the ceiling as communication bridges between the sensor modules and the hospital’s IT network.  The author notes, “signal strength dictates the number of receivers needed. Our institution comprises four main buildings, some of which were built in the late 1950s. Thus, the signal strength of the sensors in the oldest building was less than optimal and required the addition of multiple receivers to provide consistent readings. Basement areas also may require multiple receivers”.

    Temperature@lert WIFI Monitoring Device

    WiFi WTM device installed in server room provides a strong signal, good range and fast data rate without the expense of additional equipment (e.g. repeater/gateway).


    Evaluating a WTM device’s signal strength or range in all of the locations to be monitored is paramount before selecting any one technology.  Depending on the wireless technology chosen, each wireless sensor type may require more or fewer receivers to make the connection, resulting in more or less complex and higher or lower cost deployments.  NYC Hospital Queens could possibly have chosen a device that does not need a receiver (a.k.a. gateway) but had sufficient signal strength to communicate to the site’s IT network directly.  A standard WiFi device could potentially provide such capability without the added expense of a receiver/gateway device.

    Mesh network showing sensor nodes (red/green) and receivers/gateways (red).  In this case some sensors also act as gateways and can help link remote sensors without the added cost of a dedicated gateway. (Link to Source)



    Some wireless technologies are able to overcome interference from the building infrastructure, equipment or furnishings that others may not.  Other wireless technologies have mesh network capability, meaning the wireless sensors or receiver/gateways can communicate with each other.  Therefore when one device is not operating properly or experiences signal degradation caused by interference, the device can communicate with an alternative neighboring device to maintain the network integrity.  And still other WTM designs employ receiver/gateways that can contain their own temperature sensor(s) in addition to serving as a gateway, providing an additional pathway to lower the complexity and cost of the system.   Evaluating wireless devices from several vendors, each using different wireless technologies, WiFi, ZigBee, RFID, Bluetooth, proprietary, etc. can help the user understand how each works in the various locations to be monitored.


    But what does one do when these technologies don’t work or are not feasible for a hospital’s IT network?  For example, some IT departments are averse to adding new devices to their internal networks due to security or capacity capacity concerns because continuous temperature monitoring of 174 sensors in the case of New York Hospital Queens for example can generate a lot of data quickly.  To meet the hospital’s need, historical data needs to be maintained, secured, and stored for an extended period of time for regulatory purposes.  Adding alerting capability to the WTM system, for example sending email, text or phone call messages when something goes wrong, means an additional level of IT capacity is needed to send and log these alerts. Adding an escalation plan for times when issues do not get resolved in a timely manner adds an additional level of complexity.  Close collaboration with the hospital’s IT resources will be needed to determine what is possible and what is not.

    Temperature@lert How It Works


    If IT capacity or network policies make it very difficult if not impossible to add a WTM system, what options exist?  One good option is a cellular gateway that communicates directly to the wireless sensor network and uploads data to cloud based sensors via major carrier cellular networks.   Temperature@lert’s Cellular Edition is one such device.  Each Cellular Edition is equipped with a cellular transmitter/receiver that communicates through national cellular carrier networks to Temperature@lert’s Sensor Cloud web based storage, reporting and alerting services.  Each Cellular Edition can link to several Z-Point wireless sensor nodes resulting in up to 45 sensors being monitored via one Cellular Edition gateway depending on signal strength and equipment layout.


    Understanding how any new wireless network will operate at a site requires study and testing.  Once the locations to be monitored are mapped and solutions that the organization’s IT department supports are determined, those tasked with the WTM decision are ready to make their recommendation.  This all takes time and energy, so add that to the planning process and everyone will have a better understanding of who, what, when, where and why the final selection is made.  Because once this happens and the installation starts, it will be good to have the history to remind all how they got here.


    Temperature@ert’s WiFi, Cellular and ZPoint product offerings linked to the company’s Sensor Cloud platform provides a cost effective solution for organizations of all sizes. The products and services can help bring a laboratory or medical practice into compliance with minimum training or effort. For information about Temperature@lert visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.



    Written By:

    Dave Ruede, Well-Versed Wordsmith

    Dave Ruede, a dyed in the wool Connecticut Yankee, has been involved with high tech companies for the past three decades. His background in chemistry and experience in a multitude of industries such as industrial chemicals and systems, pulp and paper, semiconductor fabrication, data centers, and test and assembly facilities informs his work daily. Well-versed in sales, marketing, management, and business development, Dave brings real world experience to Temperature@lert. When not crafting new Temperature@lert projects, Dave enjoys spending time with his young granddaughter, who keeps him grounded to the simple joys in life. Such joys for this wordsmith include reading prize winning fiction and non-fiction. Although a Connecticut Yankee, living for a decade in coastal California’s not too hot, not too cold climate epitomizes Dave’s favorite temperature, 75°F.

    Temperature@lert Dave Ruede

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  • RFID and the Myth of Technical Superiority

    What is RFID and how does it compare to other SMB Server Room Temperature Monitoring Options?

    When trying to decide what solution to choose for Server Room Temperature Monitoring, IT professionals in Small and MidSized Businesses have my sympathy.  Just search Data Center Temperature Monitoring on Google and in less than a second over 10,000,000 results are found.  Who has time to go through the first 100, never mind 10 million?  And who knows if the top search results are there because they paid to be there or not?  Certainly Search Engine Optimization (SEO) ranking is in large part due to the volume of meaningful, hopefully original web content, and companies with big marketing budgets ought to dominate in this area by hiring PR firms to produce copy, blogs and social media posts. (Full Disclaimer: Temperature@lert uses paid Google advertisements and does it best to optimize SEO on a very limited budget.)

     

     

    Google search results: Data Center Temperature Monitoring (September 25, 2013)

    Recently, because temperature monitoring has been a capability added to DCIM (Data Center Infrastructure Management) offerings, IT professionals may incorrectly DCIM is equal to environmental monitoring.  This perception can become costly Small and MidSized Businesses.  In general, SMB server rooms with their limited mix of equipment housed in closets or small office spaces need robust temperature monitoring, primarily because they likely do not have dedicated air conditioning and can overheat quickly when someone turns off the AC for the weekend or when the AC unit fails.  DCIM systems can monitor the temperature and send alerts when problems occur, but their primary capability is in asset management and change control of the servers and other electronic systems.  A few rack of equipment that often ranges in age from one year to a decade or more in some cases is well served by a spreadsheet and does not need 24/7/365 accounting in most cases.

    Several DCIM suppliers have introduced RFID sensor tags into their product lineup. RFID comes in two forms, active and passive.  The tag contains an RFID device that in the case of passive is activated when interrogated by a reader that generally needs to be in close proximity to the device, up to 10 feet (3 meters) for example.  Think of the security scanner at the exits of your local department store that sounds when a tag goes through it and you’ll understand how this works.  For asset management tags would be placed on the asset to be monitored and someone would walk through the aisles with a reader to collect the data.  Assets are not continuously monitored with this approach.

    Unlike passive tags, active RFID tags have battery powered RFID transmitters and a range of 100 feet (30 meters) for example.  Tag readers are placed within an aisle or room and interrogate the tags on a user selected schedule to give near real time data collection.  Temperature and other sensors would consist of tags with thermistors or digital sensors to monitor the room’s ambient.  RFID devices operate in the same spectrum as WiFi, Zigbee, Bluetooth and related wireless devices, so in many ways are nearly identical to temperature sensors using these technologies.  Active RFID devices require regular battery replacement, often every year or two.

    Some DCIM vendors are promoting the replacement of passive RFID tags with active tags in data centers to eliminate the need for a technician to walk a reader through the server rack aisles and provide near real time data collection for improved asset security.  These factors highlight the relative newness of RFID in data center environments where radio frequencies are often challenging and the very large number needed for asset management with any granularity.

    RF Spectrum for Wireless Temperature Sensor Options (Link to Source)

    Active RFID, Bluetooth and Zigbee all require a compatible receiver to collect the data.  This could consist of the compatible RFID, Bluetooth or Zigbee receiver and an Ethernet, Cellular or WiFi connection.  Standalone WiFi temperature monitors do not require a reader because they can connect directly to the site’s network to transmit the data, making it one of the most cost effective approaches to the job of temperature monitoring. WiFi temperature monitors can often support multiple wired sensors to provide coverage in larger spaces. 

    Example of self-healing mesh network (Link to Source)

    Zigbee and related wireless devices require a reader or gateway.  They offer the additional capability of being able to connect to other sensors in a mesh network.  This capability can eliminate the necessity of single purpose data gateways such as those used in RFID systems since the Zigbee device serves both as a sensor and data pathway to nearby sensors.  And mesh network can offer a self-healing function whereby if one device fails or interference from a solid metal object blocks the transmission, the mesh network can determine if an alternate pathway is available and if so automatically switch to it and send an alert that the previous pathway is not available.  To incorporate mesh networking into RFID tags, literature has suggested pairing RFID with Zigbee, which of course adds cost and complexity and highlights again concerns about the long term RFID roadmap. (Link to Source)

    When considering temperature monitoring technology for SMB server rooms, IT professionals will want to compare the performance, cost, maintenance, and ease of use of the myriad of devices on the market.  Buying “right sized” technology can help not only meet the current need and budget, but insure the installation is up and running quickly, providing the protection the business needs and a shorter RoI.  For information about USB, WiFi, Cellular and Wireless sensors, one can visit Temperature@lert’s website at http://www.temperaturealert.com/Temperature-Alarm.aspx.

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  • RFID Switchboard features Temperature@lert Cellular Edition

    RFID Switchboard today featured Temperature@lert's Cellular Edition as the main story on their front page. The site is a community of Operations and IT executives implementing and buying RFID technology:

    RFID Switchboard Screenshot Featuring Temperature@lert Cellular Edition

    Read the full article on rfidsb.com

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