When the battery on the system falls below a specific level of charge, the uninterruptible power supply will issue a weak battery condition signal.
- You have chosen to use the four wire communication between the iSeries™ server and a uninterruptible power supply.
- The utility fail signal is active.
The controlled shutdown occurs immediately. If the system is running on utility power and the uninterruptible power supply sends a weak battery signal, the system remains up and posts a CPIO964 message. However, the system initiates a shutdown mechanism immediately under this condition if utility power is lost.
A typical factory-preset time for an uninterruptible power supply to send a weak battery signal is with approximately two minutes of runtime remaining. Some uninterruptible power supply models have an adjustable setting for this time. Ideally, you want to set it for the amount of time it takes for your system to perform a power loss controlled shutdown. Do not assume that the factory preset time on the uninterruptible power supply is sufficient for a normal shutdown of your system. Calculate the amount of time necessary to perform a power loss controlled shutdown and use an appropriate value for QUPSDLYTIM and adjust the time for weak battery signal on the uninterruptible power supply (if adjustable).
The figure shows the time progression of the QUPSDLYTIM function, from left to right.
