Caller Display has been working intermittently for some time now. I don't receive many calls but the 3 most recent (during the past week) just show as Incoming Call on my Panasonic KXTGE720E. I also have a GPO Tele746 basic dial museum piece (I like its ring, which I can hear throughout the house). When I get a call, the 746 starts ringing immediately and the Panasonic displays Incoming Call but only starts warbling after a few seconds. I dialled 1471 afterwards - in all cases the number was revealed, so was not withheld etc.
I then tried ringing from my mobile - and CD worked. Repeat: and it worked again. This time the Pano still waited before making a noise, then did so having retrieved the CD code and displayed the number.
When CD is working, the 746 usually dings once before ringing - this I gather is when the CD code is being sent. When CD doesn't work, I don't recall an initial ding.
I have tried disconnecting the 746 but to no avail.
So it does seem the CD code, which I understand is FSK coded at 1200bd (similar to a modem) is not always being sent.
CD fails several times over a few weeks and the all's fine for a few months.
It is a really useful service, so it would be good if it was reliable.
