IBM SY44-5902-05 manual Spcn power components, Primary node, Secondary node

System Power Control Network (SPCN)

The SPCN is a concept of power distribution and control for the iSeries system that makes it easier to add new system hardware units. Problems that are reported to the operating system by the SPCN are logged. You can work with the SPCN information by selecting System Power Control Network (SPCN) under the Hardware Service Manager function. For more information on how to work with the SPCN information under Hardware Service Manager, see “SPCN menu flow” on page 232.

SPCN power components

Most power components in new systems and some power components in older systems contain an SPCN node. The SPCN node contains a microprocessor-based controller. The SPCN node functions in the SPCN network and connects the points necessary for controlling power, sending commands, and reporting status.

There is one primary node in a system. All other nodes are secondary nodes.

Primary node

The primary node is the microprocessor-based controller. In stage 2 systems this node is located in the ac module, which is installed in the rear of the system. In stage 3 systems (Models 640, 650, S30, S40, and SB1) the node is on a separate card that is installed in the rear of the system. Models 600 with SPCN, 620, S10, S20, and Model 170 have the combined SPCN and system control panel functions on one card. This card is installed behind the system control panel. For Models 270 and 820, SPCN is part of the backplane. For Models 830, 840, SB2, SB3, and 890 (FC 9094), SPCN is part of the back plane in the PCI cage. The primary node is programmed to issue network commands and poll for status from secondary SPCN nodes in the network.

The primary node monitors the status of the power supplies, regulators, and backup power (BBU and uninterruptible power supply). The primary node is powered on as long as there is ac power to the frame. It communicates with the operating system by exchanging commands and network status through the control panel or service processor.

The primary node collects command responses and error status from the SPCN network and formats them for return to the operating system.

Secondary node

The secondary node is a microprocessor-based controller located in the ac module and bulk power supplies, on a card, or on a backplane. There are no secondary nodes in the 170 model.

Note: On Stage 2 secondary frames, a secondary node is located in the power control compartment (PCC). It receives power-on and power-off commands for the rack mounted units from the primary node. This secondary node controls all the ac outlets on the PCC. For more information about hardware stages, see Appendix C of iSeries Licensed Internal Code Diagnostic Aids - Volume 1.

Each secondary node is programmed to collect unit power status and respond to commands from the primary node. On stage 2 systems, the secondary node also controls the display of the following information on the rack-mounted unit display:

vSPCN address

vPower reference codes

Chapter 9. System Architecture and Configuration 231