1.   Red light (bulb removed): ON = armed / OFF = bomb dropped
2.   Yellow light (bulb removed): ON = PBK in service
3.   Green light: ON = signal to pull
4.   Switch up = horizontal bombing (ГП) / switch down = toss bombing (КАБР)
5.   Brighteness knob (ЯРКОСТ)
6.   Switch up = initial point (ВТ) / switch down = target (ЦЕЛЪ)
7.   Master switch up = ON (ВКЛ) / switch down = OFF (ОТКЛ)
8.   Left and right red arrows: course deviation
9.   Distance deviation indicator (x 100m)
10. Switch up = beacon IP (МАРКЕР) / swich down = visual IP (ВИЗ)
11. Switch up = automatic mode (АВТОМ) / switch down = manual mode (РУЧНОМ)
12. Panel lighting

This is the PBK-2 box of a Polish Su-7BKL. The Su-7B carried the PBK-1 version. On this model, there was no brighteness knob for the panel lighting. A switch was located at the same place to choose between a single bomb drop or a multiple bomb drop.

Adapted from the article entitled 'Sowjetische Atombomben in Europa - Ein  Kapitel aus dem Kalten Krieg' by Stefan Büttner, September 2008 issue of Fliegerrevue Extra 22.