MDC Call Feature on Spectra's

[fchrist16]

Can someone, in plain english, tell me so that I can tell a friend of mine this one simple fact. He has two spectra's on UHF. Both have the "call" feature and he insists they must call each other since that's what the MDC Call List and Call button were for.

What is he doing/saying wrong that he can't call one radio from another?

Regards,

-Frank C.

[AEC]

MDC1200 is an identification encoder/decode, with other features assigned to it, mainly from a dispatch console.
'Call' is a QC-II feature that uses a set of tones assigned to a particular radio, and when your assigned tones are sent, your radio unmutes, allows a 'call' to be heard, and then flashes an indicator and displays the word CALL, or CL, depending on what type of display your radio has.

In a sense, it's the same as a fire page-out used by volunteer fire depts. To page test a specific department at one time, instead of county wide.
Also to do the same task for paging specific departments to respond to a fire call.
No need to page a city dept. when a town is closer and able to respond faster....

[Bill_G]

Ha! Sounds like your friend ran into the brick wall of what an older radio can do versus what he thinks it should do. I have no experience with MDC in Spectras, but I suspect AEC is correct - that the Call feature is limited to QCII in Spectras. You would have to go through the signalling programming carefully to verify he has everything set correctly, and then experiment with it to see what they are and are not capable of.

I have used MDC to "private call" one radio from another through a conventional UHF rptr system. All the radios had MDC encode/decode with pre-ptt ani so you could tell which radio was transmitting. The decoder had an alias list so you could assign human names to an ani - ie: BOB instead of numbers. The display would clear at the end of each transmission. I also put in a call alert list so a user could scroll to the desired unit, press alert followed by ptt, and then the receiving radio would beep and display the calling radio until that user cleared it.

In general modern radios, if they have signalling options, let you encode/decode/ani/alert with QCII, DTMF, or MDC with some limitations depending on the format chosen. Those limitations always seem to be what the customer wanted to work.

[wx4cbh]

Spectras unfortunately don't have QC capability, and why MotherMoto did things that way is hard to fathom. The call feature in Spectras is MDC and DTMF based, not QC. Spectra MDC functions are in the MDC setup section in the RSS. As posted above, there are numerous options in the MDC setup for PTT ID, repeater access coding, individual and group id, individual and group calling and messaging, etc., all depending on what the requirements may be for the application.

The bottom line is that if the MDC isn't programmed and enabled for each of the channels in question, then the radio will not respond to the buttons or incoming MDC. Messaging refers to the ability to send and receive coding attached to the unit ID. That coding is usually aliased to send and display unit status things such as "in service", "out of service", "en route", "arrived at scene", "call completed", "emergency", etc. What the radio display shows when using any of the MDC related buttons or receiving MDC calls will depend on alias programming.

DTMF calling is more phone interconnect oriented. Those options are in the DTMF setup pages.

For what it's worth, MaxTracs and MaraTracs are capable of limited DTMF signalling, and limited MDC PTT ID and call response, but not the expanded messaging, yet are also capable of QC calling and responding. Go figure.

[fchrist16]

Ha! Sounds like your friend ran into the brick wall of what an older radio can do versus what he thinks it should do.

I have used MDC to "private call" one radio from another through a conventional UHF rptr system. All the radios had MDC encode/decode with pre-ptt ani so you could tell which radio was transmitting. The decoder had an alias list so you could assign human names to an ani - ie: BOB instead of numbers. The display would clear at the end of each transmission. I also put in a call alert list so a user could scroll to the desired unit, press alert followed by ptt, and then the receiving radio would beep and display the calling radio until that user cleared it.

No kidding Bill! He picked up these two radios for cheap! He was lucky in getting a control head/etc.

From the sounds of what he's saying this is what he wants to do, "private calls" between two users, but on a simplex channel. I'll be getting the two radios on my bench this evening, so if there's something I should watch out for in the programming please let me know!

The bottom line is that if the MDC isn't programmed and enabled for each of the channels in question, then the radio will not respond to the buttons or incoming MDC. Messaging refers to the ability to send and receive coding attached to the unit ID. That coding is usually aliased to send and display unit status things such as "in service", "out of service", "en route", "arrived at scene", "call completed", "emergency", etc. What the radio display shows when using any of the MDC related buttons or receiving MDC calls will depend on alias programming.

He says he has "status/messages" enabled and have text in them like "At lunch - out of car", etc but when sent from his radio (He selects the status and it auto sends?!? - again words from him) to his buddies spectra there's no ACK and no decode on the other radios end. At the same time he says he can't find where he can encode and decode MDC, as he only can set it for one or the other...My thoughts to that are NO DUH! Someone please correct me if I'm wrong.


EDIT: When I stopped by to pick up the radios just now, he had one of them on, I flipped to his frequency on my XTS5000 and had him hit the emergency button, and on my XTS the radio beeped and put out on the display EA1234, with 1234 being his MIDC-ID. Btw, this is a private security group so everyone was in the office at that time so they knew the emergency button was going to be pressed.

Regards,

-Frank C.

[akardam]

Statuses and messages are typically only ever decoded (much less ACKed) by a console. Unlike a call alert or sel call, there's nothing in sending a status or message that says which radio it is destined for, and obviously you wouldn't want umpteen subscribers on a channel all trying to ACK a status or message update at the same time - plus, really, those updates are destined for a dispatcher. I want to say that I remember a Systems Saber being capable of at least decoding a status or message, though I don't remember if it could be set to send ACKs or not.

As far as the MDC call Encode/Decode options, if you read the help file you'll see that if you select Encode, you will be able to Decode as well. Selecting Decode means you'll only be able to receive, but not send, calls.

[fchrist16]

That's what I tried telling him about the status/messages and the Encode/Decode! Perhaps now if he reads this, when I go back over there, he'll see what I'm saying!

I'm just glad that they trust me enough to program their radios after the radio shop goofed up on the programming...Now I get to bench these two radios and see what's setup and why they apparently won't call each other. We did try a Call from the Spectra to my XTS5000 after the emergency try and the XTS did not receive or ACK the call...I think something is really screwy on their radios.

Thanks all!

Regards,

-Frank C.

[fchrist16]

Well for starters it was set to decode only, not encode. Now I have my XTS5000 successfully calling each radio. My next test will be between the two radios.

Thanks for the help guys! When my buddy reads this, I think he'll give his old radio shop a nice little call...

Regards,

-Frank C.

[wx4cbh]

Well, ya see, it's like this...... If the local shop has no experience with customers with an MDC unit status system, then beyond the PTT ID and maybe MDC repeater access fields, the techs probably won't be proficient with all the whats and wherefores of MDC programming. Bad to say, but it's a more common situation than many given shops would like to admit about their personnel. Not an excuse, just a reality.

[fchrist16]

Sounds like that's it.

Regards,

-Frank C.

[fchrist16]

Ok guys, I need help again...

I went to program in the ManACK button on an A7 head and realized this...The software isn't showing it as an option. With an A9 head it shows up fine, is this feature strictly A9?

Never dealt with A7 heads before on Spectra's but assumed all their buttons are the same as an A9...?

Regards,

-Frank C.

[fchrist16]

Ok guys, I need help again...

I went to program in the ManACK button on an A7 head and realized this...The software isn't showing it as an option. With an A9 head it shows up fine, is this feature strictly A9?

Never dealt with A7 heads before on Spectra's but assumed all their buttons are the same as an A9...?

While we are at it, On the VHF Spectra's I have worked with, say radio 1234 calls radio 5678. Well 5678 sends an ACK automatically and then radio 1234 starts ringing waiting for 5678 to pick up. If one is driving, all the guys do are pick up the mic's and it's a talk only between the two of them. If one is stopped they can press the Manual ACK button to "pickup" the phone call as well and leave the mic on hook.

With the A7 head's I'm not getting that Manual ACK button, nor is pressing the PTT "answering" the call.

Anyone got ideas for me?

Regards,

-Frank C.