KVM

The KVM switch can be seen as a multiplexer that allows focusing on a single SUT (system under test) at a time. The HDMI output of each device is routed to the monitor. USB devices such as keyboards and mice are also routed in a similar way.

Routers

The routers are basically general purpose computers with an integrated Ethernet bridge and Wi-Fi modules. They can be configured to operate as Wi-Fi clients, APs (access points), or bridges. They can also operate as Ethernet switches or routers. The limited resources also allow running small footprint services such as MQTT. One router is typically used to isolate the lab network from the company / public network.

Meters

The power meters section includes SmartPower meters that can be used to power and measure the consumption of all the DC powered switches, routers, single board computers, tablets, and phones. Classic USB (not quick charge) can also be measured with adapters.

Switches

The switches serve two purposes. The routers are typically limited to 4-5 ports. Switches can be used to extend the local lab network with more devices. In addition, switches can be connected in series to measure the consumption of data transmission across multiple devices.

Cable management

The cable management module (the hole with a brush) allows routing network and power cables from the front panel to the units at the back

Small form-factor PCs

The small form-factor x86-64 PCs are tiny computers that represent low-power systems used in offices and schools. The PCs can be measured with a high-power DC meter or AC power meters.

Storage box

The rack contains a lockable storage box for various accessories, cables, adapters, and tools such as screwdrivers, pliers, multi-meters etc.

Server PC

A standard ATX system which can house external GPUs, hard drives, and other accessories. Compatible with the ATX power meter (PMD2). Currently, a desktop PC is used to emulate a server, but is missing the following features: UPS, IPMI, replicated power, multiple sockets, ECC RAM, high bandwidth I/O lanes.

The switches allow extending subnets defined by the routers. The Wi-Fi routers are typically limited to 4-5 ports per device. The switches can be used to manage a larger pool (8 to 24 ports) of network connected devices.

Odroid nodes

The Odroid single-board computers represent low-power x86-64 systems. Their power-drain behavior that is close to the one of low-power laptops. The nodes automatically boot when powered on, and can be controlled via HDMI and USB. In our setup, the typical use does not require any physical access.

Raspberry Pi nodes

The Raspberry Pi hardware is somewhat similar to some Android based mobile devices. The nodes are also commonly used in various DIY projects. The nodes automatically boot when powered on, and can be controlled via HDMI and USB. Small TFT screens can be connected and powered via the Raspberry Pi board.

Power distribution unit

The power distribution unit is located in the center of the rack to optimize cable lengths. The PDU has one input slot and multiple output slots for different systems. Even the monitors are connected to the PDU.

USB hub

If a single-board computer or a small form-factor (SFF) computer is used to run the PowerGoblin service instance, the system is usually limited by the number of available USB ports (not bandwidth). The rack contains more than six (6) USB connected meters, but the small computers usually contain at most 5 ports. One of the ports is reserved for the KVM. The ports at the front of the device are usually useful for plugging other, unspecified portable devices.

A powered USB hub allows connecting more meters to the system, but routing the messages through the hub also affects the latency of the meter readings.

Power supplies

The 19V power supplies are supply power to the Smart Power meters available via the front side of the rack. These supplies are quite heavy so in our system they're located near the x86-64 server system at the bottom.