8800sx Decoder DTMF Tone Code Whelen

Omar_Radio

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Good Morning
My Name is Omar and new at this forum and I write from Italy.
I write this questions but in US the whelen Siren is more installation but in Italy is low sistem and I have one sistem whithing 02 Consolle and 06 Siren in more town connect in Radio Simplex analog (12,5KHZ because in Italy 25KHZ dont use).
I have many test set and 8800SX Viavi and I want use for mantenance Whelen siren sistem because is hight trasportable and I have Test Automated for more brand and Test Vip Tools. My problem is decoder code DTMF generate from consolle for mantenance system and I always used HP-8920A or CMS 52 or IFR 1200S or many other and I dont have any problem. But whith 8800sx in encoder tone to Test Set to Siren OK, the siren in recived code. But I want recived comand Tone from Consolle or diagnostic code tone from Siren the test set dont work right exmaple :
Tone Si Test Command general To generate to Consolle at Siren in DTMF STD WHELEN Mark 40 ms Space 20 ms My CODE is 121100#1DC . I decoder this tone the HP8920A is ok but I use decoder 8800sx decoder many code 1210#1DC or 2210#1DC o other code . But I generate other code to Consolle EXAMPLE 124586842# the test set decoder the tone the problem appair in repetitive code.
I write Viavi and send screen shoot setting test set but i dont have a reply.
I write in this community for have a consideration at this problem to understand if this has happened to you too or if you have solved it in some way

Tanks

Best Regard Omar
P.S I apologize if my English is incorrect

MODERATOR: Changed DTMF codes to different but similar info to mask the actual control codes of the users system.
 
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Keith

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Omar, yes there is a bit of difficulty in the English translation here but I think I see what you are getting at.

Are you trying to DECODE (receive) the DTMF tones with the 8800 monitor or are you trying to ENCODE (send / transmit) the DTMF.

The 8800 is a nice monitor and has a number of functions that the HP doesn't but the HP is a better piece of equipment at lest in my opinion.
The part here that got lost in translation is the repetitive code. Is the 8800 sending the code over and over? That would be a setting on the 8800 or using the burst button and not the continuous button.

Also, you may want to consider removing the specific DTMF code you are using for your systems from the post or have one of the moderators do it.
There are only certain parts of the forum that are blocked from the web crawlers and the Google search engine. Posting that information may well make it public and I am not sure you would want that.
 

Avery Johannssenn

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I believe he's saying the code with consecutive number 2s is throwing errors.
 

RFI-EMI-GUY

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I believe he's saying the code with consecutive number 2s is throwing errors.
And zeroes as well. The 8800 must be too slow in decoding the tones (too much hysteresis in the logic) and is entirely missing the inter digit space. The manual for that monitor is very poorly written.

I am so happy with my HP8920B and its operation and documentation.
 
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Omar_Radio

Omar_Radio

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I apologize for my mistake and ask the moderators to remove the code entered in the first post. for the answers I am happy with the 8800sx but my post was to understand with some expert like you in the USA how the 8800sx behaves with dtmf codes. In Italy the dtmf are not used but the selectives are used then now digital modulation is used but these systems are still in Analog and for practicality, using a light test set for the service would be more convenient.
have noticed that even changing the Firltri in the decoder part by putting 03-3K HP or trying other filters the decoding does not change and the instrument behaves in the same way. The post was born to understand if you use the same tool for decoding codes for Whelen systems since we bought 8800sx and for just over a year and just bought I have performed maintenance on these systems without problems now after updating the FW to 2.4.4 to use the Vip tools option it seems to me that something has changed but I could be wrong. The last 8800sx came back from the Calibration performed by an official distributor since for quality every year we calibrate the instrumentation in our possession. I am fully aware that HP8920A is still a current and performing machine for analog systems but carrying a 20kg test set is tiring.
Thank you very much for your interest
 

RFI-EMI-GUY

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I would direct the problem back to Viavi as they probably have badly written decoder code. Perhaps a video comparing the HP8920A vs the 8800SX will get them to pay attention. There are various smartphone APPS that will decode DTMF strings. Perhaps that might be a work around. Also there were some standalone DTMF decoders made by various US manufacturers for the LMR and Telecom markets. I agree, my "portable" HP8920B, never leaves my workbench.
 

Keith

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Now that I have a better idea of your issue, it's true that decoding Whelen DTMF is very difficult for service monitors, and most DTMF decoders that are not Whelen product.

One piece of advice I could give is to get in contact with Whelen and get the current version of the programming software for the Whelen sirens. With that software and a serial cable you can actually connect to the siren controller (if it's a 2020 or 2030 board) and turn on a DECODE function that will display the actual DTMF digits that the siren is decoding in real time. Then you can see what the siren is seeing and know that it's getting the right information. I can not speak to the cost of the software as I am a Whelen dealer and they provide it to their dealers.

I can say that a 2600 series service monitor will encode the DTMF but will not decode it and we had issues with the early 8800 Aeroflex monitors doing either.
I still carry a 2600 monitor for this reason is it's simpler to use for basic function tests than to get out my 2010 encoder and radio and set it all up. Program the system I am working on (I work on a number of Whelen systems with different system codes and some systems that have multiple system codes), and do basic tests.... But it's very handy for doing remote testing of sirens before I arrive on site to be prepared with parts if the siren is a two way siren and is at least partly operational.
I get status information on amps / drivers, rotor, battery voltage and any current alarms the siren is generating.

Battery voltage is KEY for bringing sets of batteries and the test is as simple as clearing the counters, Silent testing the siren a couple time and looking at the minimum voltage the controller reports. While not giving away ALL my service secrets, I will also know a set of batteries is really bad if I run a status test and get a reply but then run a Silent Test and have the siren NOT reply then run a status test again in 5 minutes and get a reply back (the radio and control board will run off the battery charger and transmit the siren status. Batteries that are out of capacity will charge to full voltage in that time frame but the minute they have a load put on them they die.
 
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Omar_Radio

Omar_Radio

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Keith,
Thanks for information your information was very useful to me since you know these systems very well, I wanted to inform you that I have the Whelen diagnostic and programming software and I have a 400W resistive load to test systems without using the sirens to test battery efficiency and all the circuitry. And we have been maintaining these systems for about 10 years.