Here you have various advanced Z-Wave options. Use these options only if you understand what they mean. Most users will not need these options.
Polling is the process where Vera tries to ask a Z-Wave device for its current status, like if it's On or Off, at what temperature, and so on. This is how Vera knows when the status of a device changes, such as when the temperature has changed if it's a thermostat, or if you manually turned a light on or off. Normally Vera attempts to poll one Z-Wave device every 10 seconds, and Vera polls the devices in order until Vera has polled all of them. So the delay between polling nodes depends on how many nodes you have. If you have 6 nodes, each node will be polled once a minute, and if you manually turn a light off, within a minute or so Vera's dashboard will show the light is off. But, if you have 100 Z-Wave devices, it can take 16 minutes before Vera has polled them all. You can change the polling behavior by going to the 'Options' tab on 'Zwave device' from the Toolbox.