ICOM IC-M506 Radio

VHF Marine Band radios, protocol, radio communication theory, practical advice; AIS; DSC; MMSI; EPIRB.
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Location: Michigan, Lower Peninsula

ICOM IC-M506 Radio

Postby jimh » Fri Dec 07, 2018 9:53 am

If you are considering buying an ICOM IC-M506 VHF Marine Band DSC radio, you should be well informed before selecting the particular model. This radio is available in five different configurations, and when ordering the radio you should be careful to select the particular version you want for your installation.

Model IC-M506 is the basic model, designated M506-01. It has a front-mounted microphone and NMEA-0183 only. This model does not display any AIS information even if connected to an external AIS receiver data output via either NMEA-0183 or NMEA-2000.

Model IC-M506 PLUS is available in two versions. Both include NMEA-0183 and NMEA-2000. The front-mounted microphone version is designated M506-11; the rear-mounted microphone version is designated M506-31. Neither version has an integral AIS receiver, but both versions will show AIS targets on their display if connected to an external AIS receiver via NMEA-2000. These models do not display AIS data if connected to an external AIS receiver via NMEA-0183. Models with NMEA-2000 have an additional component, the UX-232 subassembly.

Model IC-M506 AIS is available in two versions. Both include NMEA-0183, NMEA-2000, and an internal AIS receiver. The front-mounted microphone version is designated M506-21; the rear-mounted microphone version is designated M506-41. Neither model sends any AIS data via NMEA-0183; AIS data is only sent via NMEA-2000. Models with AIS have an additional component, the UX-231 subassembly. Since the AIS option is only available on radios with NMEA-2000, these models then have both the UX-231 and UX-232 subassemblies.

When buying an IC-M506 in any model, be certain to get a product that has the latest firmware revisions installed for both the radio and the AIS receiver. There have been several firmware updates since initial production of the IC-M506 radio that provide remedies for problems encountered in the original firmware. As far as I can tell, the firmware in the IC-M506 radio cannot be updated in the field by the user. The firmware updates are not generally available for download, and installation of new firmware requires a specialized computer application and two specialized cables to make the connection to the radio from the host terminal executing the specialized software. If you purchase an IC-M506 radio with older firmware, the radio may have to returned to a service center to have the firmware updated.

The most recent firmware update occurred November 7, 2018. This means that there is a very good probability that a radio sitting on a dealer shelf that was shipped before that date will have out-of-date firmware.

A knowledgeable user has reported that if two IC-M506 radios are installed on the same NMEA-2000 network, there is a serious malfunction in their operation which produces an alarm for loss of GPS signal. For details see this well-written and well-illustrated explanation of the problem and the failure of ICOM to provide a remedy:

Icom M506 NMEA 2000 problems
http://www.mvtanglewood.com/2016/04/ico ... ssues.html

Although mentioned above, particular notice should be made that the AIS receiver in the IC-M506 radio does not output any AIS data via NMEA-0183. This can be a significant problem for interfacing to chartplotters which need AIS data on their NMEA-0183 input in order to display the data.

Although there was a serious anomaly in the NMEA-2000 behaviors of the IC-M506 radio, and the radio omits any output of NMEA-0183 data for AIS information, the NMEA organization bestowed upon the IC-M506 radio an award for "Best VHF Marine Radio" in their judgement in three consecutive years, 2014 to 2016.

Here are press releases attesting to these awards:

2016: https://www.nmea.org/Assets/2016%20nmea ... s%20v4.pdf

2015: https://www.nmea.org/Assets/10.nmea_201 ... ds-rev.pdf

2014: https://www.nmea.org/Assets/2014-nmea-p ... inners.pdf

ICOM also made specific claims for the basis on which the IC-M506 radio was able to win the award, saying that it "...captured the [2014 NMEA Best Radio] title based on its NMEA 0183/2000 plug-and-play functionality and integrated AIS receiver..." and "...also recognized for its new intuitive user interface, which promotes fast access to radio functions and settings like Class D DSC." I could not find any statement from NMEA to affirm these criteria. Note that the ITU recommendation on digital selective calling sets specific requirements for the user interface on ALL Class-D DSC radios, and compliance with those criteria are mandatory for any DSC Class-D radio to be sold in the USA.

It seems a bit incongruous that the NMEA organization could award a "best" designator to a device that omitted AIS output on one of its NMEA interfaces. Also, the integration of an AIS receiver into a VHF Marine Band Class D DSC radio was, by 2014, already achieved earlier by other brands, notably Standard-Horizon, who pioneered the practice. The principal distinguishing feature of the IC-M506 would seem to be its NMEA-2000 interface, but that, too, was already available in other Class D DSC radios such as the Lowrance LINK-8 or SIMRAD RS35.

It should also be noted that the IC-M506 radio is a "NMEA-2000 certified product." NMEA explains what that means:

Only “NMEA 2000 certified” products meet the rigorous and mandatory software
requirements. The certification process tests equipment to ensure the products meet the
conditions established in the NMEA 2000 Standard. NMEA 2000 defines the message
formats for transmitting electronic information amongst products. NMEA 2000 also
defines certain messages that all products must implement and use correctly. These
required messages are what make it possible to add devices to the backbone and use them
with little or no configuration required. Only those manufacturers that have passed the
NMEA certification tests can use the NMEA 2000 logo and market their products as
NMEA 2000 Certified.

I do not know what the test "conditions established in the NMEA 2000 Standard" actually are because I have not purchased the standard--it would cost perhaps $3,000 to $5,000 for me to buy it. Further, the contents of the standard cannot be disclosed, so even if I bought the standard, read it carefully, and found the precise details of what tests must be conducted and met, I could not tell you about them.

The fact that the firmware in the IC-M506 radio has been revised several times and there continues to be a reliable report of a significant bug or anomaly in the NMEA-2000 behavior of the radio seems to render the notion of being a "NMEA-200 certified product" as having perhaps less significance than one would like to expect. I don't know this for a fact, but I would presume that one element of being a certified product would be that connection of the product to a NMEA-2000 network should not cause harm to other devices on the network, a test that this radio appears to fail.

Posts: 11862
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: ICOM IC-M506 Radio

Postby jimh » Mon Dec 10, 2018 9:16 am

Regarding the cables needed to perform a firmware update to an ICOM IC-M506 radio, here are some possible sources for them:

Icom OPC-478UC USB Cable: $51

More information available from: https://www.ameradio.com/doc/Icom_cloni ... cables.pdf

Icom OPC-980 Cloning Adaptor Cable:$23
https://www.ameradio.com/product/260994 ... ption.html

In addition to these cables, to perform the firmware update you must have the actual firmware update files, the communication software to connect the radio to the terminal, and a terminal to host and execute the communication software.

Posts: 11862
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: ICOM IC-M506 Radio

Postby jimh » Mon Dec 10, 2018 9:34 am

Regarding the communication software needed to perform firmware updates to an ICOM IC-M506 radio, the ICOM CS-M506 software is needed. Here is a possible source for the software:

ICOM CS-506 Cloning Software: $87
https://www.ameradio.com/product/261195 ... ption.html

The software is provided on a CD-ROM disc. A CD-ROM disc reader will be required to use the software. The software also comes with a dongle to authenticate the installation. The software is intended for execution under the Microsoft Windows operating system versions Windows 8/7/Vista 32bit/XP.

Posts: 11862
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: ICOM IC-M506 Radio

Postby jimh » Mon Dec 10, 2018 9:41 am

Let us review all the hardware and other elements necessary to install updates into an ICOM IC-M506 radio:

  • USB cloning cable and driver software
  • Cloning cable adaptor
  • Host terminal running Windows proper version
  • USB port on host
  • CD-ROM on host
  • 12-Volt power on bench for radio to be updated
  • Cloning software
  • Successful installation of USB driver and configuration of serial port
  • Successful installation of cloning software and training on its use.

You are now ready to perform the update. The only items lacking are:

  • The actual firmware updater packages from ICOM
  • An FCC license that permits you to make modifications to VHF Marine Band radio transmitters; typically a General Radio Operator LIcense is required; because the radio is a DSC radio, a GMDSS installers license may also be required.

Once you have obtained the actual firmware updates and the FCC licenses, you are now ready to install the firmware.

Although ICOM has public download sites for firmware updates for many of their products, I have not discovered any firmware update download sites for the IC-M506 radio. I believe this is due to the regulated nature of a VHF Marine Band radio, which requires that only licensed technicians can perform any modifications to these radios.

Posts: 11862
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: ICOM IC-M506 Radio

Postby jimh » Mon Dec 10, 2018 11:44 am

Here is a list of firmware updater packages for the ICOM IC-M506 radio, from a secondary source. Note the most recent update is from November 7, 2018, just a month ago:

Firmware Version
Associated Software
Update Summary
Introduction Date

Main v1.101
UX-232 v1.007, v1.3
Fixed loss of GNSS position with Latitude and Longitude near 0 degrees

Main v1.101
UX-232 v1.006, v1.3
Updated DSC

Main v1.1,
UX-232 v1.006, v1.3
Improved GPS over NMEA bus

Main v1.1
UX-232 v1.005, v1.3, v1.2
Improved DSC performance

Main v1.004
UX-232 v1.005, v1.1
Hang up during device search fix