pyronix delta bell g2 wiring to replace ventcroft compact classic

[ianinglis@ianinglis.]

i am trying to replace my old ventcroft compact classic with a new pyronix deltabell plus g2 but the wiring has me (and others) confused
my old bell box has 5 wires

STB
HOLD OFF +
HOLD OFF -
RTN
TRG

the new box has the following

BACKLIGHT DISABLE
T
T
ENG HOLD
STB
BELL
12V+
12V-

can anyone suggest the correct way to wire this up please??

 

[Bigsosij]

STB = STB
HO+ = 12V+
HO- = 12V-
RTN = T
TRG = BELL
Link spare T terminal to 0v (dependant on type of control panel)