: Model is also designed with dual hot-swappable redundant Power Modules. In addition, the Sentinel 32 offers field replaceable, modular eight-port circuit cards, modular network and console port connections, and an analog modem option. The dual network and console ports are also field replaceable. A dual network/console/modem module is available which replaces the second console port with an analog modem. In addition, the Sentinel uses hot-swappable circuit modules that allow for field replacement of groups of eight serial ports without affecting the other ports.