Moxa Technologies EDS-508 user manual Max. Age sec, Enable STP per Port, Port Priority, Port Cost

EDS-508 Series User’s ManualFeatured Functions

Max. Age (sec.)

	Setting	Description	Factory Default
		If this device is not the root, and it
		has not received a hello message
		from the root in an amount of time
	User adjustable	equal to “Max. Age,” then this
		device will reconfigure itself as a	20
	numbers	root. Once two or more devices on
		the network are recognized as a
		root, the devices will renegotiate
		to set up a new Spanning Tree
		topology.
Enable STP per Port

		Setting	Description		Factory Default
		Enable/Disable	Select to enable the port as a node		Disable
			on the Spanning Tree topology.
NOTE	We suggest not enabling the Spanning Tree Protocol once the port is connected to a device (PLC,
	RTU, etc.) as opposed to network equipment. The reason is that it will cause unnecessary
	negotiation.
Port Priority
		Setting	Description		Factory Default
			Increase this port’s priority as a
		User selectable	node on the Spanning Tree	128
		number	topology by inputting a lower
			number.
Port Cost
		Setting	Description		Factory Default
		User adjustable	Input a higher cost to indicate that
			this port is less suitable as a node	200000
		number
			for the Spanning Tree topology.

Port Status

Indicates the current Spanning Tree status of this port. “Forwarding” for normal transmission, “Blocking” to block transmission.

Configuration Limits of RSTP/STP

We should point out that the Spanning Tree Algorithm places certain limits on three of the configuration items described above:

[Eq. 1]: 1 sec ≦ Hello Time ≦ 10 sec

[Eq. 2]: 6 sec ≦ Max. Age ≦ 40 sec

[Eq. 3]: 4 sec ≦ Forwarding Delay ≦ 30 sec

3-29