There are plenty of options for creating low-cost wireless nodes, that can be used as remote monitors; basically putting the functionality of digital voltmeters, oscilloscopes and logic analysers on a wireless network.
The low cost and simplicity of these devices means that they can be scattered around as required; embedded in the equipment to be monitored, rather than being briefly attached when a problem appears. This is particularly useful in remote or hazardous locations, where ‘fit and forget’ equipment monitoring removes the need for difficult site visits.
Lean2 