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Field Report: Broadcast Tools Audio Sentinel

Field Report: Broadcast Tools Audio Sentinel

Jan 1, 2011 1:00 AM, By Michael Bradford, CPBE

I must admit before another word that I am an old timer: I started in broadcasting in 1962 working part-time after school and on weekends at WCCW in Traverse City, MI. I must also admit that I was slow to accept the Internet as anything more than a convenient method to find equipment, parts and an occasional article that piqued my interest.

Several years ago, however, I started to realize that the Internet offered an amazing alternative method of program delivery, remote control and monitoring for broadcast. The one area that kept me from plunging headlong into this realm was reliability. Now, after installing and programming numerous Internet and Web-based products, I have to admit that reliability is no longer an issue. I acknowledge that the level of reliability comes from reading many articles about other engineers’ experience and knowing what to demand from the IP provider.

Performance at a glanceWeb-enabled
Two-channel silence monitor
Integrated stereo switcher
E-mail logs
Audio switching

With that said, I began studying and field-testing products from many manufacturers and vendors relating to IP-based equipment. Right from the start, Broadcast Tools has embraced the IP Network and offered many of its famous “tiny tools” that utilize this method of delivery.

I also learned many years ago to approach a project from a “reverse engineering” strategy; that is, study, analyze and determine what one piece of equipment should provide to fulfill the requirements of a project, then search-out the piece of equipment that fits those requirements. In this fashion, I can eliminate buying several pieces of equipment to respond to a future need that was overlooked in the initial analysis.

This is where the Audio Sentinel came to my attention. I had a client with a microwave system for primary program delivery and an ISDN circuit for emergency audio feeds. Ownership decided it wanted the ability to manually switch the ISDN audio feed to on air along with maintaining the automatic changeover via the STL’s squelch relay. Having recently installed a DSL circuit at this location, access to the Internet was available. Then the news from the ISDN provider that their new rates would be three times the previous rate! Plus, we had an ISDN failure several times during the previous three months where the response was measured in days, not hours. To top it all off, this provider had petitioned the FCC to abandon ISDN service all together. The writing, as they say, was on the wall.

Reverse engineering

As I sat and compared my “reverse engineering” chart and the features of the Broadcast Tools Audio Sentinel, the solution became clear. Here is a Web-enabled, two-channel silence monitor with an integrated stereo switcher and the ability to send logging e-mails, along with up to eight e-mail recipients should any alarm situation occur. It has three internal relays that are user-programmable for manual operation and/or automatic sequencing. The Audio Sentinel can be controlled and monitored locally, remotely over any IP network, including private networks, IP-based industrial control networks or, of course, the Internet.

If you have one of the spanking-new hand-held devices that uses a Web browser or is Web-enabled, you can routinely receive reports and alarms as well as manually control the Audio Sentinel from anywhere with Internet access. The Audio Sentinel can even be programmed to send a special sound effect to play on your PC speaker when an alarm is received.

One SPDT relay is dedicated to indicate which stereo audio source is connected to the main stereo output. Two more SPDT relays can be configured to perform numerous user-defined tasks, including action-sequences related to an alarm situation.

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Field Report: Broadcast Tools Audio Sentinel

Jan 1, 2011 1:00 AM, By Michael Bradford, CPBE

SNMP capabilities provide for multiple units to be monitored with any SMNP manager software. SMTP username and passwords are supported too.

All audio and relay connections are via the Broadcast Tools standard euro-block screw connectors. The Internet NET connector is the standard RJ-45 port, and power is provided by the included 7.5Vdc external power supply. Front panel indicators show valid audio present, while the “PWR/Heart Beat” indicator slowly flashes to indicate processor operation and power. Separate indicators show which input is selected and there is a manual select button for local operation of the Audio Sentinel that duplicates the rear-panel remote/ext connection.

No goody-box required

Because the Audio Sentinel comes with both straight-through and cross-over CAT-5 cables, you don’t need to check your goody-box for these cables for programming and normal connection to the Internet. Connection to your PC and programming your Audio Sentinel is straightforward, as step-by-step instructions are provided. The necessary IP address data can be obtained from an IT manager. In my case, the Gateway, Broadcast ID, Subnet mask and specific IP address data were supplied by the IP provider prior to installation. Again, step-by-step instructions are included for customizing your Audio Sentinel as much or as little as you require. Password protection is standard and you can select the level of access for eight users; three levels include monitor only, full remote control or administration. The Audio Sentinel will also generate a show-log to display which input is active, what day and time an alarm was generated, the relative audio level for each input channel and other parameters. You can choose when or if to send show-log reports via e-mail to up to eight recipients.

The audio switcher is programmable for level detection, time delay before switching, alarm generation and automatic or manual operation. In my case, the out-of-state programmer can access the Audio Sentinel via Internet, enter the assigned security code and monitor all parameters, check the alarm show-log and manually select the alternate audio source to feed the on air processing. This is great for EAS or weather emergencies, or special programs that can originate from anywhere in the world by an external, IP-based audio codec. (That’s a whole story in itself!)

Broadcast ToolsP
[email protected]

Each audio source can be labeled as it will appear on the Web page for the Audio Sentinel during initial set-up, so operators can easily identify what they are monitoring. Setting up the e-mail addresses for the alarm notification and show-logs is a one-time event, but you can change data or add data anytime via the Internet once your Audio Sentinel is installed and operational.

By the way, note the warning in the manual about using the Save Settings button when you are done with the various programming entries or you will be entering those settings again!

Also note that your new IP address data will not take effect until you power-down the Audio Sentinel when you’re finished with programming. You can easily make changes and enter new data once you have made the final connection to the Internet.

You can download the manual for the Audio Sentinel from the Broadcast Tools website and study it along with your own “reverse engineering” sheet prior to arrival.

Now when the STL burps during heavy fog or loss of power at the primary studio location, the switch-over to the auxiliary audio source occurs within the prescribed time and generates an immediate alarm e-mail message to me, the studio and the network headquarters in another state. If there is a live, remote broadcast anywhere, it can be routed to the auxiliary source input on the Audio Sentinel and seamlessly switched to on air … all over the Internet. Special announcement during un-manned hours? No problem. This can easily be handled by a single operator at the main OpsCenter located in another state.

I could go on and on with the other features and site-specific programming for my Audio Sentinel, but I recommend you download the manual from and check it out for your specific needs. You will be pleasantly surprised.

Bradford is the owner of Broadcast/Audio Services, Jackson, MI.

Editor’s note: Field Reports are an exclusive Radio magazine feature for radio broadcasters. Each report is prepared by well-qualified staff at a radio station, production facility or consulting company.

These reports are performed by the industry, for the industry. Manufacturer support is limited to providing loan equipment and to aiding the author if requested.

It is the responsibility of Radio magazine to publish the results of any device tested, positive or negative. No report should be considered an endorsement or disapproval by Radio magazine.

January 2011

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