[texecom veritas r8 - Display says "UNSET ALARMS" and it's flashing "T"]

I know my usual code, but not an engineers code.  Yes, it's a keypad with LCD display.

it when into 'tamper' because I was being nosey in our basement not realising that unscrewing the box that I found would activate the alarm!

[texecom veritas r8 - Display says "UNSET ALARMS" and it's flashing "T"]

No, nothing. 

[texecom veritas r8 - Display says "UNSET ALARMS" and it's flashing "T"]

I moved into the house a couple of days ago.  There's no manual, and CODE doesn't work.  How would I reset?

[texecom veritas r8 - Display says "UNSET ALARMS" and it's flashing "T"]

Ok, so like a dingbat I removed the front of the main control box, not realising that there was a tamper alarm that was activated, requiring me to turn off the alarm using the control panel.  I'm a wally.  But now the display on the control panel says "UNSET ALARMS.......T" with the 'T' flashing.  I can't remove the message despite typing in my 4-digit PIN or pressing RESET.  Any ideas what I can do?