The 58°OFF LED comes from the NTF Field Discriminator Box (Bartelson Box) as the
HEP Permit signal. This signal is derived from the AND of the transductor signal,
the Hall probe & the inverse of the 58° Ramp Enable signal.
The 58° Ramp Enable
signal is a gate which is turned on by a TCLK $1A event (NTF Enable) and off by a TCLK $1B
event (NTF Disable).
Therefore, the NTF 58° MAGNET OFF LED will only show the magnet OFF between
$1Bs and $1As.