Solution
The Fieldbus specification defines the Link Active Scheduler (LAS) device to poll a list of addresses by sending a Probe Node (PN) packet to each address in its list of addresses. This allows devices to come online during normal operation. The specification also describes how to tell LAS to skip probing certain addresses in the range in order to speed up the new devices detection on the bus (or devices that are having their addresses changed).
The two parameters involved in maintaining the unpolled region in the list are called:
- FirstUnpolledNode (FUN): tells the LAS the beginning of a region of addresses not to probe
- NumOfUnpolledNodes (NUN): tells the LAS the length of that region
These parameters can be modified by opening the
Network Parameters under the
link interface and selecting the
Link Settings (Advanced) tab. Change the
FUN and
NUN value to allow specific addresses to be assigned to the device.