IBM 3745 Series, Hardware Maintenance Reference

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Power OFF Sequence.
The normal power OFF sequence is initiated by :
Ÿ
Manual power OFF at the control panel if the machine is in local mode.
Ÿ The remote power OFF (RPO also called RMPO for VTAM) signal, if the machine is in network mode.
Ÿ The drop of the last host power hold signal if the machine is in host mode.
Power ON │ Power OFF
Sequence Sequence
│
┌──────────────────────────┐
│ │ │
Power ON ────┘ └───────────────────
│
┌──────────────────────────────────┐
│ │ │
Main Cont. Com. (K1) ──────┘ └─────────
│
┌───────────────────────────────┐
│ │ │
PS ON ─────────┘ └─────────
│
┌─────────┐ ┌─────────────┐
│ │ │ │ │
POR ──┘ └────────────────┘ └───────
│
──────────────────────────────────┐
│ │
Power Hold └────────────────
│
┌────────┐
│
│ │
Power Pick ────┘ └─────────────────────────────────────
│
┌─────────────────────────────┐
│ │ │
Sequence Complete ───────────┘ └─────────
│
Scheduled Power ON Function
The purpose of the clock used in the power control subsystem is to keep time and calendar date through
extended power OFF periods. This will allow scheduled power ON actions to be taken at a predetermined
time and day of the week, independently of any intervening AC main power failures. Each day of the
week may be associated with a different power ON time.
The logic for the scheduled power ON function is in the PCC card and is powered by a battery during AC
main failures.
This function is available in network mode (2 at power control window) only, and is allowed or inhibited by
the customer through the MOSS.
Chapter 10. Power System
10-23