hook flash disconnect supervision

[mjwald]

So I am trying to get hook flash disconnect supervision to work.
We have quite a few emergency devices out and about that require disconnect to drop the line, most are happy with loop reversal to do this, and it works great.
Our elevator phones however, want the hook flash disconnect. But it just does not appear to work, I have "tested" the elevator phones themselves, by simply shorting the pair, and the phone drops right away.
Reading the NTPs there is nothing to this, just activate ISP and your good.

We have a CS1K rls 7.62
The analog stations are on OPS cards NT1R20AB
I have ISP pushed all the way up to 250 ms hoping to see something, but no.
And as I said, everything that has OSP 1 set works great, just not the stations with ISP
What am I missing?


TN 036 1 06 00
TYPE 500
CDEN 4D
CUST 0
MRT
ERL 00000
WRLS NO
DN 4655 0 MARP
AST NO
IAPG 0
HUNT
TGAR 1
LDN NO
NCOS 4
SGRP 0
RNPG 0
XLST
SCI 0
SCPW
CLS UNR DTN FBD XFA WTA THFD FND HTD ONS
LPR XRA AGRD CWD SWD MWD RMMD LPD XHD SLKD CCSD LND TVD
CFTD SFD MRD C6D CNID CLBD AUTU
ICDA CDMD LLCN EHTD MCTD
GPUD DPUD CFXD ARHD OVDD AGTD CLTD LDTD ASCD SDND
MBXD CPFA CPTA DDGA NAMA MIND
MCRD
EXR0 SHL ABDD CFHD
CWND USMD USRD BNRD RTDD RBDD RBHD FAXD CNUD CNAD PGND FTTC
CDMR PRED MCDD T87D SBMD PKCH MPTD ELCD
PLEV 02
PUID
UPWD
AACS NO
MLWU_LANG 0
FTR ISP 250


Thanks Much!

 

[StanleySteamer]

A few things to try:
1. Reverse the tip & ring polarity and test. I know, it's supposed to be a "hook flash", but the NTP says the NT1R20 actually gives a disconnect "by the removal of the ground connection to the tip lead". Worth a try.

2. The CDEN for the NT1R20 should be DD since it's an 8 port card. I doubt it would have an affect on unit 0 but maybe. Also, remember to skip every other pair on jumper field when you connect units 1 to 7.

3. Try the Viking CPC units.

https://www.vikingelectronics.com/product-details.php?pid=346

https://www.vikingelectronics.com/product-details.php?pid=497

These will work on a regular NT8D09 line card with LDTA in the CLS. The disconnect signal will be a few seconds slower while the CPC units detects a return to dial tone, but they work well for the elevators phones that I have installed them on.

 

[mjwald]

Thanks for that, reversing the polarity did not do it.

Called the vendor, going to let him figure it out

 

[Wanebo]

Have you tried testing whether the flash is being sent? A simple VOM connected to the wires would show a momentary voltage drop on disconnect.

We had the same issue on a few pieces of equipment and no matter that we proved to the vendor that we were sending the disconnect they insisted that their equipment worked with other systems so the problem must be our system. I installed a few Viking CPC's to sense silence on the lines and force disconnect and haven't had a problem since.