Command State 92337-92357 and 93023-93266

The above diagrams represent the P/E, RNG, and PEN logic with P and E equations modified to accept events that trigger the low guard threshold. The equations for P/E, RNG, and PEN events are:

Event type

Coincidence equation

P, E

P1.P2.P4*.AH*

RNG

P1.P2.P4.AL*

PEN

P1.P2.P8

The buffers into which "orderly" events can fall are as follows:

Range

No guards triggered

Low, not high guard triggered

High guard triggered

P1

NONE

NONE

NONE

P1 through P2

P/E

P/E

NONE

P1 through P3

P/E

P/E

NONE

P1 through P4, P5, P6, or P7

RNG

NONE

NONE

P1 through P8

RNG, PEN

PEN

PEN

This differs from the launch command state in that the P and E (and corresponding rate) equations were changed to accept events where the low guard threshold was triggered. This was because shortly after launch it was discovered that the centers and guards of P3 were subject to intermittent crosstalk, which sometimes caused valid (particle not entering the guard rings) PHI events to be vetoed because the crosstalk caused the guard to trigger. After another brief test, the instrument was returned to this state for most of 1993.

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