Compaq GS160, GS80, GS320 manual Power System Manager Module

2.3.6Power System Manager Module

Each QBB has one power system manager (PSM) module. This module monitors CPUs, voltages, temperatures, and blower speed in the cabinet and reports this information to the system control manager (SCM).

Figure 2–10 Power System Manager Module

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The PSM module is connected to other PSM modules and the SCM micro- processor (located on the standard I/O module) through the console serial bus (CSB). The SCM is the master; the PSM can only operate as a slave. The PSM controls the powering on/off and resetting of all modules within the QBB and of the QBB itself. The PSM also contains three I2C bus interfaces and a serial I/O bus channel to each CPU in the QBB. The PSM module retrieves information from the I2C EEROMs residing on the CPUs, memory modules, and the QBB backplane. The PSM uses a serial I/O port connection to communicate with one CPU module at a time. The PSM can only perform a function as the result of a request from the SCM.

2-14 AlphaServer GS80/160/320 User’s Guide