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920MHz Band Wireless Device (Korea) USERS MANUAL EM-9121 Rev. 1
7.1.11 EXAMINING PACKET FILTERING SETTINGS
Enable packet filtering to operate a system where an upper device polls transparent models and overlapped or delayed packets in
the wireless network are discarded.
[Table 7.14] Packet filtering settings
ITEM
PARENT
CHILD
EXPLANATIONS
Packet filtering
*
1
Required
Required
Enable (Yes) or disable (None) the packet filtering function.
When enabled, delayed packets, etc. are discarded according to the filter time-
out on polling.
Filter timeout on polling,
parent device
*
2
Required
–
Setting required when the packet filtering is enabled.
Set a value subtracting the fixed overhead (1 sec.) from the valid polling time of
an upper device (e.g. data acquisition device).
Range: 10 – 600 (100 msec. increments)
Filter timeout on polling,
child device
*
2
–
Required
Set a value greater than the polling response time.
Range: 10 – 600 (100 msec. increments)
*
1. Set to ‘None’ so as not to operate in a polling system.
The setting must be identical in the same network.
*
2. Timeout period must be longer for the upper devices (parent device) than lower devices (child devices).
7.1.12 EXAMINING FIXED ROUTE SETTINGS
In joining a network, a wireless device attempts to connect to a device with the highest RSSI value among the devices with the same
PAN ID as explained in “7.1.2 PAN ID (GROUP NUMBER)” on page 54.
However, the fixed route function enables a device to connect with a specified destination regardless of momentary RSSI values.
In addition, the temporary detour function enables a device to transmit data via the detour when the radio wave status to the fixed
destination is poor.
When the device fails to transmit data to the fixed destination, it retransmits data via a detouring route, if any.
Detouring three times switches the route to this detouring route temporarily even if the fixed route is available.
The registered fixed route is adopted again when it is re-established (in several tens of seconds to several minutes).
Specify a wireless device which is one-hop upstream as a fixed destination.
The downstream route is calculated automatically.
Consider use of this function when building a network in an environment where the radio wave state is unstable.
[Table 7.15] Fixed route settings
ITEM
PARENT
CHILD
REMARKS
Fixed route
–
Required
Enable (Yes) or disable (No) the fixed route.
Destination short address
–
Required
Short address of the fixed destination
Temporary detour
–
∆
Enable (Yes) or disable (No) the temporary detour when the fixed route is
enabled.
*
1
∆: The value can be left at default.
*
1. When a wireless device joins the network, unless the device receives the radio wave from the fixed destination, the participation in the
network is not allowed even when the temporary detour is enabled.
