Emergency Alert System & Common Alerting Protocol / EAS CAP

clockHere is a summary of some basic info about CAP, the new protocol for emergency alerts.

Update as of 11/23/2010: The FCC has extended the deadline for CAP compliance to September 30th, 2011!

CAP Frequently Asked Questions

What is CAP?

CAP stands for Common Alerting Protocol. CAP is a new internationally-accepted open standard for sending information about emergencies. In the US, CAP is going to be implemented as part of the IPAWS (Integrated Public Alert Warning System) program. FEMA will originate messages about emergencies and send them to a centralized “aggregator”, which will then disseminate the messages over the internet.

Unlike the current EAS system, where messages only go out over TV and radio, CAP is not tailored for broadcasters. CAP messages may include text, photos, videos, or audio to supplement the basic information. The messages will be sent not only to TV and radio stations, but also to computers, smart phones, highway signs, and more.

At this point, CAP is not a replacement for the previous emergency alert system. It’s more of a supplement. You can think of CAP as an extra input to your EAS. While you used to be required to monitor two radio stations with your EAS, now you’ll be required to

monitor CAP as a third information source as well.

Who runs CAP?


Each state will be responsible for developing its own system for implementing CAP. You should check with your local State Emergency Management office to find out what sources to monitor and what content will be delivered via CAP. One addition in the new rules is that broadcasters will be required to play messages from their state’s governor, in addition to the test and presidential messages that already have “must carry” status.


What do I have to do, and when?

At a bare minimum, the FCC requires you to be capable of receiving and decoding CAP messages within 180 days of September 30th, 2010, when FEMA announced that it was adopting the new protocol. This means the deadline for compliance is March 30th, 2011. A coalition of broadcasters has asked the FCC to extend the deadline because the FCC is still ironing out some of their new EAS rules, but we don’t know yet whether the FCC will extend it.

As of right now, you won’t actually be required to broadcast the CAP messages – though if you get an important public safety message, we recommend that you pass it on! Eventually you will probably be required to integrate CAP messages with your other EAS messages.

How can I receive and decode CAP messages?

There are a few options for this. If you have a “CAP capable” (or “CAP-able”, as we like to say) EAS, then all you’ll need is a software update. However, most older EAS models aren’t CAP capable. If you have a non-CAP capable EAS then you have two options:

1) Buy a new EAS that is CAP capable, or

2) Buy a CAP-to-EAS converter that can receive CAP messages and convert them to the standard EAS format

A new EAS will probably cost upwards of $2000, depending on what exactly you need. CAP-to-EAS converters start at $1350. If you’re interested in participating in a group buy, please contact Maggie (maggie AT prometheusradio DOT org). In any case, you’ll need an internet connection, because CAP messages are sent out over the internet. See the end of this document for more specifics on equipment.

What if my station cannot get an internet connection?

Great question! The FCC hasn’t addressed this yet. If your studio is located in a place where internet access is limited, let us know. We’ll talk to you about your options, and we may ask to use your story in our advocacy work with the FCC.

Are there exceptions to the rules for Low Power FM stations?

No, the rules apply to all radio stations. However, if your station is an LPFM, the requirements still say you only need to decode (not encode) EAS messages. Keep this in mind if you buy a new EAS, because decoder-only models are generally cheaper.

Is it better to buy a new EAS or a CAP converter?

A converter will be cheaper, but not by leaps and bounds. If you can afford the extra cash, there are a few advantages to buying a new EAS. If you get a CAP capable EAS, it may be easier to access the additional content (like audio or video) in the CAP message. A CAP capable EAS will also offer better integration between traditional EAS and CAP messages, while an old EAS with a converter may have trouble if a CAP message and an EAS message come in at the same time.

Some specific notes on EAS models and converters, grouped by manufacturer

Digital Alert Systems

Digital Alert Systems is developing a software package that will allow their EAS units to receive CAP messages. The package isn’t on the market yet, but they say it will cost $895 for the basic version and more for a version with text-to-speech capabilities. The software will work with all EAS boxes made by DAS, including decoder-only and encoder-decoder models and newer and older generations.


Trilithic offers a network card interface for the EASyPLUS EAS at $995. They will provide a free software update in January that will allow the EAS to receive and broadcast CAP messages.

Gorman Redlich

Gorman Redlich does not yet have plans to make a CAP-capable EAS. They do make a CAP-to-EAS converter with a list price of $1350. The converter is compatible with EAS models made by other brands.


TFT doesn’t currently make a CAP-capable EAS. They do expect to have a CAP-capable EAS within 18-20 months, but it will be aimed at TV stations and they estimate that it will cost $8,000-$10,000. TFT also makes a CAP-to-EAS converter for $1600.

Unfortunately, some of TFT’s EAS models only come with 2 audio inputs, which isn’t enough to monitor two standard EAS sources along with CAP. For the 2-channel encoder/decoder models (911R2 and 911T2), TFT offers an audio input expander for $495 that increases the number of inputs to 4. For the 911D, there’s no option of expanding. TFT recommends that 911D users ask your State Emergency Management Office for a waiver to be allowed to replace one of the original EAS sources with a CAP-to-EAS converter, but we have no indication that these waivers will be granted.


Sage makes a new EAS model, the Sage Digital ENDEC, that is capable of receiving CAP messages. It will need software updates as the CAP standards evolve, but these updates are free. Older Sage units are not CAP-capable. The new Sage EAS costs $2695.

Where to learn more

Here are a few links to further resources on EAS CAP:

FAQ from the Society of Broadcast Engineers:


Free webinar from the Society of Broadcast Engineers:


FAQ from Radio Mag Online: