Batboard

I understand somewhat of what failsoft is: Network fails or something else serious, the subscriber units will enter Failsoft, and switch to a pre-defined frequency (if programmed to) and operate in conventional mode.

Am I right so far?

What happens if there is NO control channel at all (power failure, out of range)? Would that cause radios to enter failsoft, or would they just sit there and not do anything?

I have been goofing around with failsoft settings, and so far all I can make the radios do is give me the "no-you-cant-talk-beep". Now, before I get in trouble... No, I am not on any trunking networks and I am not attempting to gain access to anyone elses, I was just trying to make a couple radios failsoft themselves into simplex, .

Since we just had a radio failure drill and it's fresh in my mind...

When the system goes into failsoft the base stations begin to transmit on predetermined frequencies and transmit a tone along with the carrier called a failsoft word. When your radio can no longer receive anything on its preset control channels it then listens on the failsoft frequency for a carrier with the failsoft word. If it doesn't receive a carrier with the failsoft word it will then honk at you and tell you its out of range.

At least that's how our radios are configured, others might be different.

You've got it right. It's not really a tone, it's low-speed data that is sent out that is the failsoft word. The radio will also emit an audible tone on a regular basis to indicate that the system is in failsoft, as well as display "FAILSOFT" on the display if the radio has one.

Digital failsoft is generated in the AstroTAC comparator on a voted/simulcast system, analog failsoft is generated at the voting comparator (DigiTAC), and in single-site systems each individual repeater generates it. The comparators generating failsoft allow the system to continue operating in a simulcast & voting configuration even in the event of the loss of site controller.

Most systems these days have redundant controllers, so failsoft is much less frequent than it was in the past. I've only ever encountered a failsoft condition in the systems I maintain twice, the first time was due to a software bug in the controller (new system too, THANKS MOM), and the second was due to latched major alarms in both site controllers due to the customer not noticing the problem fast enough and reporting it to us.

In SmartZone systems, there is also a failure mode called Site Trunking, but that's another ball of wax I won't get into unless you want me to.

I'd like to hear it if your willing to talk (well, er... type).

+1

Hello there!

I do work in the widest radio trunking system in Mexico, we have over 50 sites working in one big Zone and another Zone with almost equal sites, both of them operate in a Type II Protocol from Motorola Smartzone in analog technology, but we are expanding into digital now (P25).

I’m responsible from at least over 1300 subscribers at my zone and over 10 sites around, so I think it’s an interesting test field!

Site Trunking: It will appear each time that a repeater site loses its connection with the master site (Site Controller), it could be due to a failure in the physical connection of the "data cable" from the repeater site into the media connection (microwave for example) or the media connection itself (for example due to "fading" in microwave connections), but, it can be also due to a failure in all of the "voice connections" from the site repeater to the Master Site. In other words: there is no control from the Master Site to the Repeater Site (all voice channels or the control channel). In this way of operation, the repeater site doesn’t lose the control of itself.

Failsoft: It means that there is no longer control in the repeater site, no matter what about the control channel or the voice channels are from the Master Site to the Repeater Site, the repeater(s) that can act as "control" of the repeater site are not able to work properly, so the control channel "disappears" (for example: turning off the repeaters that can act as "control channel".

By the way, i can tell by my experience: if you do not program a radio to work in failsoft and the repeaters are not programmed as well, you could take the risk of losing your communication without notice it! The radios will not show nothing on the display, no beep or message at all, but you won’t be able to Tx by pressing PTT, no matter that they are programmed to alert and display SITE TRUNKING or OUT OF RANGE INDICATOR or IMBALANCED COVERAGE INDICATOR.