I thought I had read some where that I can use PoE to power the Cisco Physical Access gateway along with a local power supply to provide some power fault tolerance. Is this correct?
The recommended method is to use PoE or external power, but not both. If you connect both, the external power will be used over the PoE, and if the external power fails, the Gateway will reload as part of the swtich to PoE. Sometimes this can cause issues when the external power is restored. The recommended way to provide redunancy is at the PoE swtich (multiple power supplies and power feeds) or via monitored external power supply. If you are using external power, we recommend that you disable PoE on the Gatway swtich port. The PoE is not designed to be a hot backup for the loss of external power.
Hope this helps,