3Com 3C81600 User Guide - Page 19

Using the Advanced RPS 19 The SuperStack unit is supplied with power from an AC mains supply. A power module is connected using the standard DC cable to the RPS socket on the SuperStack unit (see Figure 9). If the internal power supply fails, the SuperStack unit enables the Advanced RPS. CAUTION: If the product you are connecting to the power module does not have the auto-enable feature, ensure the mains cable is removed from it before attempting to connect it to the Advanced RPS. When the Advanced RPS takes over supplying power to the SuperStack unit, the unit may reset, as in a power cycle. Some SuperStack units, when set up in this configuration, can use the Advanced RPS as their primary source of power. In the case of Advanced RPS failure, the SuperStack unit's own PSU acts as a redundant power supply and will take over supplying power to the SuperStack unit. Please refer to the documentation that accompanies the SuperStack unit for more information. Figure 9 Advanced RPS Managed Redundancy Configuration Full Redundancy This is the mission-critical mode of use, offering full redundancy. This configuration provides the most resilience for your network. The SuperStack unit takes no power from the AC mains supply, and should not be directly supplied with mains power. A 'Y' cable connects two power modules to the unit, providing full redundancy (see Figure 10).