DTMF on XTS5000's

Richard · Post by **Richard** » Wed Sep 22, 2004 9:34 pm

Just bought some XTS5000 (model threes) from the big M. I was supprised that even despite the full keypad...the radio will not have a flash available until DECEMBER to support a hot keypad DTMF....abviously not the same capabilities there as the XTS3000...anybody been told any more on this? You would think that for over $3400 a copy they would at least do DTMF.

Post by **alex** » Thu Sep 23, 2004 5:32 am

Probably current demand for the radios from big buyers are for Trunked systems, where Hot-Keypad is a conventional only option - you really don't use DTMF signaling in P25 applications (someone please correct me if I'm wrong).

If you had to design something to meet a few million in incoming business, then you'd probably design around that market first....

-Alex

ASTROMODAT · Post by **ASTROMODAT** » Thu Sep 23, 2004 12:13 pm

First off, they have been saying that hot keypad on the XTS5000 will be available in "a month or so" for the last 10 months, so I wouldn't hold your breath for December. Second, I understand that the first offering will now be Hot Data 12 dialing in ASTRO, and analog DTMF may happen sometime later, if ever at all.

BTW, checking the latest 4Q 2004 Motorola Price Book (which came out about 1 week ago), the DTMF option on the XTS5000 is only shown under "Conventional" operation (e.g., no DTMF in Trunking), and it merely states"Future" in the Capabilities matrix.

Also, the XTS5000 will not be able to encrypt Data 12 packets (e.g., when your voice is encrypted in ASTRO mode with DES-OFB, AES, etc.), so you are a bit vulnerable here if someone has the right lash-up and knowledge (e.g., a DIU 3000, with an ASTRO TAC, or a Quant tuned to your input or output could decode your Data 12 packets, and discover your command keys, etc.).

Larry

P.S. Yes, Alex, you are correct that there is no such thing as DTMF in ASTRO mode. The Data 12 packets are decoded by the DIU 3000 at the "Patch" port (on the DIU's rear panel), where they are converted into anlalog DTMF tones. This is one of our gripes about both the IFR and GD test sets----none of them (so far to date) can decode Data 12 packets, so you have to get out a spare DIU 3000, connect it up to either a spare ASTRO TAC RX. or a spare Quantar, in order to check on proper Data 12 packet signaling operations. What a pain!

Post by **/\/\y 2 cents** » Thu Sep 23, 2004 4:11 pm

DTMF on P25 is sent as a packetized command rather than read as a tone I believe....thats where they are hung up I bet. Just push the PTT down and do the DTMF w/ your other finger. No biggie. Hot DTMF is nice though, esprcially for an application I have in mind.

ASTROMODAT · Post by **ASTROMODAT** » Thu Sep 23, 2004 5:14 pm

I must be misunderstanding your post, but I'm not at all sure what you are saying, My 2 Cents. In the digital P25 mode, when you go ASTRO (be it VCELP or IMBE), there is no way to directly send analog DTMF tones, since DTMF is an analog signaling technique. One can choose to either 1) press the keypad in a so-called "hot dial" fashion, or 2) you can choose to send out digits from pre-stored phone numbers (or any kind of numerical sequence---it matters not). Either way, digital Data 12 packets (not analog DTMF tones) are then sent out over the air.

Note: Keep in mind that while in the analog FM mode, these pressed keys (or generated number sequences, your choice) will, indeed, send out traditional DTMF tones. They can be set for continuous, or a pre-programmed timed pulse duration, depending on what you set in the CPS.

However, in the ASTRO mode, you can NOT directly send out analog DTMF tone(s). Instead, you either 1) press the keypad or 2) send from a pre-stored sequnce list. In either/both cases, under P25 ASTRO digital mode, so-called "Data 12 packets" are sent over the air.

I recommend that you review the APCO P25 specs if you'd like tons of further technical info on the makeup of these tightly defined APCO standard Data 12 packets.

In P25 mode, the next step is that the DIU 3000 decodes these Data 12 packets. They "appear" at the RJ-45 MRTI "Patch" port on the rear apron of the DIU 3000. At this point, the DIU 3000 to MRTI cable carries DIU decoded/recovered analog DTMF tones to/from the MRTI. The ASTRO Data 12 packet digital data that was decoded into analog DTMF (via the DIU 3000) is normally used to interconnect with the MRTI. However, as we have done on our system, you can also use these tones to interface to a variety of controllers. Also, the DIU 3000 has the reverse capability: It can decode input analog DTMF tones from a Tone Remote and/or a MRTI, and encode it into Data 12 packets to be transmitted over the air via the Quantar repeater. The DIU sends these D 12 packets up to the Quant via the internal ASTRO modem in the DIU, and they "arrive" at the Quant via its (optional) internal ASTRO modem.

You have to remember that the DVSI IMBE chip does not, and can not, decode DTMF. However, there is on-board additional code on the DVSI IMBE chip that DOES decode D 12 packets. In close harmony with custom Motorola code in the DIU, this allows it to spit out recovered (albeit regenerated) DTMF.

Hope this helps clarify.

Larry

Post by **/\/\y 2 cents** » Thu Sep 23, 2004 7:00 pm

I meant what you said in a nutshell.

Richard · Post by **Richard** » Wed Sep 29, 2004 9:29 pm

To clarify my original posting.....
All I want on my $3500.00 radio is a hot keypad with push-to-beep (with the PTT depressed) to sent out DTMF in the analog, conventional mode.

It would seem as if the XTS5000 does not have the same capabilities there as the XTS3000 (or the HT1250 for the matter).

I do also agree, I have recently seen the "future" option in the price book on the conventional DTMF square.

RKG · Post by **RKG** » Thu Sep 30, 2004 7:16 am

We get around this by programming any channel we want to be able to send keypad DTMF on (for instance, for remote programming of devices over the air) as follows: enable phone on the channel, set the dialing range to "Unlimited", and set the dialing mode to "immediate live."

You also have to either program a button to enter phone mode or a menu item to do the same thing. To be sure, a couple more steps than is required to send OTA DTMF on a venerable ICOM U-16, but it works.

(Tip: when programming the phone parameters, be sure to delete the default "phone access" digits or you'll get some extra stuff sent each time you invoke phone mode.)

Karl NVW · Post by **Karl NVW** » Thu Oct 14, 2004 1:44 pm

Might as well correct one error in ASTROMODAT's post right now: Today's P25 is ALWAYS IMBE vocoding, it does not include any compatibility with VSELP, and Motorola's implemetation never has supported VSELP on a 9600 baud control channel system.

ASTROMODAT · Post by **ASTROMODAT** » Thu Oct 14, 2004 2:43 pm

My point was, and is: In the digital mode, whether it is IMBE or VSELP, the XTS3000, ASTRO Saber and the ASTRO Spectra mobile radios can send Data 12 packets via their respective keypads. In all cases, the DIU 3000 can decode these Data 12 transmissions and generate the respective DTMF tones at the MRTI port on the back of the DIU 3000. Of course, the DIU 3000 will need to have the proper firmware to handle IMBE versus VSELP. It is correct that there is no such thing as P25 VSELP, but that really wasn't relevant to my point. I think the issue was more around the question of sending DTMF when in the digital mode (IMBE or VSELP), and how this works.

Hope this helps.

Larry