sundance-communications.com/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems SVM-400 Not detecting a caller hang up

BT have told me than our line is still classed as a residential type, they can change it to a PBX line which they think would solve the disconnect signal problem!

but by doing this we would lose the function of 1471

i doubt this will fix the problem...... The SVM should pick up the disconnect tone from any line... i thought on the logic board 816 there is a jumper that controls the waveform? maybe this is only on the DCS(200)
Maybe your SVM-400 is configured for a different geographical region and doesn't understand the disconnect tone.

ive put a voltage meter on my line,

when idle on hook its at -47.8V
when ringing it jumps to around 50V
but when SVM-400 answers the incoming call it goes to -6.0V
When it finally disconnects the voltage goes back to -47.8V

I unplugged the SVM-400 and rang the line again.

when idle on hook its at -47.8V
when ringing it jumps to 51V

the line disconnects fine without the SVM-400.

I have the SVM-400 plugged into the wall using the ground came inside the plug, i havent used an external ground.

Anyone got any ideas???

What happens if you answer an incoming call on an extension and the caller hangs up - does the DCS-816 disconnect the call immediately or does it think the call is still connected ? If it's the latter the problem isn't with the SVM-400.

I know the manual says the minimum CO SUPV TIME is 100mSec, but I'm pretty sure I set it to 80mSec to cure a similar problem (trunk to trink conference calls not clearing), this was on a later version DCS-816 with 2.0x firmware.

i just rang the system on my mobile, the SVM-400 answered the call and transferred it to the ring group where i picked up the phone, i hung up on my mobile, i heard the drone tone of an ended call down the phone but the line light was still lit and the call timer was still counting!

i could even transfer the call to another extension!

BTW ive changed around the BT Drop cables into the master socket, i.e. 2 > 5 and 5 > 2

now i was a line voltage of around 48V (it was around -48V before)

when the call is answered by the SVM-400 the voltage drops to 6V, when the call disconnects it goes back upto around 48V again!!

Line polarity doesn't matter on modern phone systems, Samsung included.

A line voltage of 5-10v when off-hook is normal, should be the same if you pick up the extension or let the SVM-400 answer.

It definitely sounds like disconnect supervision rather than anything to do with the SVM-400, see if you can reduce the CO SUPV TIME to 80mSec.

It might sound daft, but I presume you did pick UK for the country when you first setup the DCS-816.

ive resent the whole system!

when i come to re program it, im asked to select the country! so i select UK and press TRSF to save!

then when i go back to country, it is back to NONE!!!!

it wont save now!!!!

sorted the country problem!!!

BT need to set the Clear disconnect timers to 800ms. The analogue lines wont clear otherwise.

Although it is a residential line, they still have disconnect timers.
The best way to sort this issue is to call BT and ask them first what the timers are set to. Don't mention 800ms until they tell you what they are currently at.
You need to turn your battery switch on too!

I think this thread has gone as far as it can in the open forum. Please everybody, read the terms of service. We are talking about selecting countries and battery switches which is not permitted in the open forum. We do not need someone defaulting there system and being without service. It's time to to take this off the board or better yet, get a qualified technician on site.

Thank you everyone for your cooperation and understanding.