AC4490 User Guide
Version 4.5
Laird Connectivity Solutions Support Center:
http://ews-support.lairdtech.com
26
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Radio Interface
The Radio Interface section manages the following settings:
Interface Timeout Interface Timeout specifies a maximum byte gap between consecutive bytes.
When that byte gap is exceeded, the bytes in the transmit buffer are sent out
over the RF as a complete packet. Interface Timeout is adjustable in 0.5 ms
increments and has a tolerance of ±0.5 ms. The Interface Timeout should not be
set below 2. The default value for Interface Timeout is 0x04 (2 ms) and should be
adjusted accordingly when changing the transceiver baud rate.
RF Packet Size
RF Packet Size is used in conjunction with Interface Timeout to determine when
to delineate incoming data as an entire packet based on whichever condition is
met first. When the transceiver receives the number of bytes specified by RF
Packet Size without experiencing a byte gap equal to Interface Timeout, that
block of data is processed as a complete packet. Every packet the transceiver
sends over the RF contains extra header bytes not counted in the RF Packet Size. It
is much more efficient to send a few large packets than to send many short
packets.
CTS On/
CTS On Hysteresis
(Flow Control)
See
Flow Control
for more information.
Max Transmit
Retries
(For clients and
servers in Point-
to-Point networks
only)
This value represents the maximum number of times a particular data packet will
be transmitted unsuccessfully, or without an acknowledgement, before the
AC4490 discards the packet. The default value is 16 attempts. If communication
is lost and the client's Link LED is on, try increasing this value in small increments
until communication is reestablished.
Note: This value is always associated to client radios and server radios in Point
to Point Mobile. The valid range of values for this field is 1 to 255.
Broadcast
Attempts (Point-
to-Multipoint
only)
This value represents the number of times a data packet will be transmitted by a
transceiver in Broadcast Mode. The default value is 4 attempts. If communication
is lost and the clients' Link LED is on, try increasing this value in small increments
until communication is reestablished. Valid values for this field are 1 - 255.
Note: All Broadcast Attempts are used whether the packet was received
without error by the receiving radios or not.
Range Refresh
Range Refresh specifies the maximum amount of time a client reports in range
without hearing a server beacon. Each time the client hears a beacon, it resets its
Range Refresh timer. If the timer reaches zero, the client goes out of range, takes
In_Range
pin High and enters acquisition mode to find the server once again.
The range refresh is equal to the hop period (20 ms) x Range refresh value.
Note: Range Refresh should not be set to 0x00.
Radio RF
The Radio RF section manages the following settings:
Client / Server
Designates AC4490 type. In each network, there must be only one server. All other
AC4490 units must be programmed as clients. The number of clients in the network
is not limited; however, if performance diminishes, consider additional RF Networks.
