This is from the Avidyne website:

https://techsupport.avidyne.com/portal/kb/articles/ex500-ex600-mfd-software-4-2-faq-s

EX500/EX600 MFD Software 4.2 FAQ's

For EX600 & EX500 MFD-equipped aircraft:

•For ADS-B OUT

-Avidyne offers IFD4XX/IFD5XX FMS/GPS navigators for approved GPS position source

-AXP340 Panel-mounted or AXP322 Remote-mounted Mode S Transponder

•For ADS-B IN

-EX500/EX600 MFD customers can now upgrade to R4.2 MFD software

-R4.2 adds display capability of FIS-B Weather using Capstone-standard ADS-B IN protocol and ADS-B/ADS-R/TIS-B Traffic using ARINC735 protocol.

-Avidyne offers SkyTrax100 Series ADS-B IN Receiver

-R8.2 also adds compatibility with 3rd-party systems including Lynx NGT-9000, Garmin GTX345, FreeFlight RANGR-RX, or other Capstone/735-compatible ADS-B IN receivers.

Q: What's Included in R4.2?

•Adds support for Avidyne ADS-B IN weather products using on EX500 & EX600 Series MFDs

-Supported ADS-B/Wx products include NEXRAD, SIGMETs, AIRMETs, winds and temps aloft, METARs, and TAFs, plus TFRs

•Allows EX500/EX600 MFD to display ADS-B Traffic when wired to a compatible ADS-B receiver that provides traffic via ARINC 429/735 protocol

-MFD will display legacy TAS symbols, not ADS-B directional traffic

•R4.2 is specifically for the support of ADS-B and is not required or recommended for any other reason.

Q: What's removed in R4.2?

•R4.2 removes support for Sirius weather from the MLB700

•R4.2 removes support for Iridium-based satellite weather from the MLX770

•If you are currently using either of these systems and want to continue to do so, do not upgrade to R4.2 as you will not be able to go back.

•(Note: support for XMD-076/A is NOT removed)

Q: Can I use a 3rd Party ADS-B Receiver (GTX345, L3 NGT9000 Lynx, etc) with R4.2?

•A: Yes. In addition to adding compatibility with the Avidyne SkyTrax 100 Series ADS-B receiver, R4.2 will allow your EX500/EX600 MFD to display the same weather products from a GTX345, Lynx NGT-9000, Free Flight RANGR-RX, or other Capstone-compatible ADS-B IN Rcvrs.

Q: I currently have a TAS6XX series traffic system, can I still use the TAS AND get ADS-B In traffic?

•A: Yes. Avidyne’s new SkyTrax600 (aka TAS-A Release 2) allows TAS6XX series customers to upgrade to SkyTrax600 capability which blends Active-surveillance (TAS) traffic combined with passive (ADS-B IN) traffic for display on your EX-series MFD

Q: I currently have a SkyWatch TAS, can I still use the TAS AND get ADS-B In traffic?

•A: Customers will need to choose between SkyWatch TAS and ADS-B traffic on the MFD in Maintenance Mode. This is not selectable by the pilot. Some customers are displaying ADS-B Traffic on their GPS display and keeping their SkyWatch displayed on the MFD (or vice versa). For now, Avidyne recommends keeping your SkyWatch TAS for traffic as most aircraft are not ADS-B out equipped yet. There are some ADS-B IN/OUT transponders that accept Skywatch/TAS input and blend it with ADS-B traffic on the ARINC 429 output, in which case the EX MFD would display both.

Q: I lost my Sirius weather when it was terminated by WSI/Sirius XM, do you offer a satellite-based weather solution?

•A: No, we currently do not have a replacement for the MLB700. With the proliferation of ADS-B in the market, we have not made any specific plans to develop a replacement for the MLB700 at this time. If you prefer a satellite-based weather solution we recommend a portable receiver and an iPad as a solution. Currently, the SiriusXM SXAR1 is available from Sporty's for $399 after rebate.

Q: I currently have an XMD-076 XM receiver in my airplane. Do I need to remove it to get ADS-B weather?

•A: During configuration, you have to select one datalink weather source to the EX500/EX600 MFD from the XM receiver or from the ADS-B IN Receiver, but you cannot have both. Some customers want to remove the XM and get rid of the subscription fee associated with that service, while some other customers are choosing to leave the satellite-based XM connected to their EX-series MFD and displaying ADS-B weather on their Avidyne IFD4XX/5XX GPS Navigator display (or elsewhere). It really all depends on pilot preference.

Q: I already have a GTX345 in my airplane. Will R8.2 allow me to display ADS-B Traffic & Weather from the GTX345 on my MFD?

•A: Yes. This also holds true for any other compatible 3rd party ADS-B receiver (Lynx/RANGR) that is already installed.

Q: Will Avidyne feature a promotional pricing with the launch of R4.2?

•A: Yes. We are currently running a promo for customers who purchase an IFD550 with a Lynx NGT-9000 from Avidyne, we will also include the R4.2 software upgrade for free for your EX500/600 MFD.

Q: Do I need to send any hardware in to Avidyne?

•A: EX500 & EX600 MFDs must come back to Duncan Aviation for updating. Please note the R4.2 upgrade is not covered under warranty.

Q: How much does R4.2 cost?

•A: Please contact Duncan Aviation for pricing and scheduling. Additional costs may be associated with the upgrade. Contact Duncan Aviation for details at 800-562-6377.