Hello, all, I would have tagged this off if my old post, but it is now closed. We’ve been converting all of our sites/phones to VoIP and freepbx, and that has been great. However our security panels have been left our of the equation in this conversion. I bought some HT801’s & HT802’s for experimentation. I went to put one in place, and before I did, the current, Alarm “Secuirty” guy said that they wouldn’t work, because the system he put in needs to sense, “Low Line Voltage”…I thought these HT801’s and HT802 would do that as well…Does anyone know if they do? Any help would be greatly appreciated.
These unit should provide a High-Z “signal” to the alarm. His alarm circuit needs to be plugged into an FXS port, and you should be able to simulate whatever his alarm circuit needs are with that. Now, there may be a requirement for the B+ power (for lights, etc.) that the FXS may or may not support, but that can usually be compensated for the way Ma Bell used to it (providing power on the Black/Yellow pair).
So, ask him if he means the auxillary B+ or normal On-Hook power. If the former, there are other solutions. If the latter, you should try it and see.
Finally, it might be time to lean on his expertise. Is he saying that the HT- isn’t going to work, or that no FXS is going to work? If the former, get his solution. If the latter, reassure him that the HT provides a compliant FXS port and it should work fine.
Okay, for anyone who cares, I answered my own question. Even though the “Security Guy” said it wouldn;t work…I hooked it up, and it did. So the HT801 & HT802 work with both the Vista 128, and Vista 50 Panels. Thanks!
Dave you also helped 
You gave me the encouragement just to hook it up and try it.
1 Like
Okay, so Discovered a new problem today. The Panel can be called, But the panel cannot call out from this HT801 box. Are there any settings we can try on the FXO box to get it to dial all…I called Vista Support for the security panel, and basically they said the reason it dosen’t dial out is something to do with DTFM and POTS…
Without knowing what the “something to do with” was told to you, it will remain an ongoing mystery 
.
Possibly they need to see a full 48v battery, many ATA only do 24V (viking have solutions) DTMF is just BS, it hasn’t changed since 1956.
1 Like
Yeah, I’ve been told the DTMF is bullshit…I found out what numbers the Panel is calling to the Receiver station (Monitoring station) and I dialed them from the HT801, and sure enough, I get a response back from the receiver…with fax like dial tones…so with my pathetically limited knowledge I’m stumped…The 48V may very well be, but getting any straight answers from the Panel support company has been hell…that’s where the Ma Bell bullshit DTFM story came from…
Many UL rated panels require a 48V battery before they will ‘Line Grab’ get a $5 dollar multi-meter from ebay.
An expensive analog “butt set” will also let you listen to the line when the panel tries to seize the line. Plug it in and you can listen to the call as it goes out.
It is a “UL” Rated panel, the security guy told me that.
Okay, I will see what I can do for this, and then reply back.
Then likely only PSTN lines are indemnified, your insurance company might well not pay out on VOIP service, even if it works, yeah a completely 1960’s thing.
Yes, we are aware that this might be the case…RIght now management seem to be willing to accept the risk, doe the decrease in longterm costs…I will grab a multumeter and check the voltage coming out of the HT801. Okay, please excuse my ignorance in advance, if it did require 48V, is there such a device that would “boost” the power up with the signal after it leave the HT801? Thanks in advance.
But a surplus cisco router with an FXO/FXS interface is probably a cheaper way to get 48V
( I seem to remember that tyhe audiocodes stuff also does 48v)
Okay, that was going to be my second question, is there anything cheaper ha ha ha. Okay, one more question don’t laugh me out of the room yet, since you’ve given me options, but is this also doing the same thing as the devices you’ve recommended:
https://www.sandman.com/longloop.html
Or is this a different beast?
Same claimed beast, no experience so no opinion, Viking stuff is pretty rock solid.
I would never put Elevators or fire alarms on VOIP, its just an unfortunate and unnecessary liability (even if the ‘acceptabe’ PSTN line is directly from an AT&T IP-FLEX Cisco Router over g729 ) I just won’t expose my clients to such BS, the Insurance companies have better lawyers and deeper pockets than I.
This is a good point. The more I hammer at this, the more the acceptable risk seems to become an issue, in my eyes anyways. Dicko, one more question, after you lead me in the right direction in regards to the 48V, I went and read a about how alarm panels work, especially legacy ones. I guess my only question is.(and I hope I word this right), SInce my alarm panel CAN receive phone calls, upload and download data, but does not make calls, does that mean my panel is smart enough to check for 48V when the line if, “Off Hook”, and this is why it won’t, “Make the call”, and is it normal (used loosly), for a panel to receive a call, and cease the line, even WITHOUT 48V, but not make the call? So I guess what I’m asking is, is it normal to receive, but NOT make calls if the 48V is not detected? (Because that’s the behavior we have right now).
Next step is to realize that the “fax tones” you hear are actually the ‘ademco’ protocol used by your Vista panels and most other US UL rated ones. So you NEED unimpeachable g711 , g729 won’t work, If you are inquisitive you can enable asterisk’s app_alarmreceiver which will decode it,
Absolutely normal behavior is in fact a ‘line grabber’ which is required to hangup any call on the line and continue to attempt the call from the attached FXS device to your subscribed monitoring service until it fails this is always done with an electro mechanical relay (because it is more reliable ? , look at what the original computer bug was ), one fail condition, often shown by red led on the panel is low BAT. Otherwise it contacts the monitoring service which will negotiate a dump of the condition and act if necessary , this also usually happens early every morning as a ‘check condition’)
Okay, yeah so now I’m wondering, is the HT801 making the calls, but does it NOT know what to do with the ademco protocol when it receives it…Is that why you say start there first?
Or sorry the freePBX does not know what to do with it…