The CBUS voltage and current meters may be used to display track voltage and current on the layout, if suitable hardware is being used. Availability of meters will depend on the hardware connection.
The Cbus meters listen for a fixed messages with ACON2 opcodes from node 65534. An Event number (EN) of 1 indicates a current reading whilst and EN of 2 indicates a voltage reading. This may change to being user configurable in future.
Depending on the hardware connection it may be neccessary to use a Node Variable (NV) or some other mechanism to configure the hardware to send the current and/or voltage readings on the CBUS network. The frequency (update rate) of the readings is hardware dependent and not mandated by JMRI or the CBUS specification.
In PanelPro meters may be added from the tools menu or from the CBUS tools menu. In
DecoderPro3 the meters are currently only available from the CBUS tools menu. 
CBUS® is a registered trade mark of Dr Michael Bolton