Murata Electronics North America DNT900 Benutzerhandbuch
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©2008 by RF Monolithics, Inc.
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DNT900 - 11/05/08
bits 7..2
Not used
bit 1
If set to 0, the base can pass a new ARQ_AttemptLimit to the remotes
If set to 1, the remotes use the existing ARQ_AttemptLimit in Bank 1
bit 0
If set to 1, the base will send broadcast packets ARQ_AttemptLimit times
instead of once.
ARQ_AttemptLimit -
this sets the maximum number of attempts that will be made to send a data packet
on the RF link. Setting this parameter to the maximum value of 63 is a flag value indicating that there
should be no limit to the number of attempts to send each packet (infinite number of attempts). This mode
is intended for point-to-point networks in serial data cable replacement applications where absolutely no
packets can be lost.
should be no limit to the number of attempts to send each packet (infinite number of attempts). This mode
is intended for point-to-point networks in serial data cable replacement applications where absolutely no
packets can be lost.
TDMA_MaxNumSlots
- in TDMA access modes, this sets the number of slots that are allowed. In fixed
slot mode, this allocates the number of slots directly. In dynamic slot mode, this sets the maximum num-
ber of slots that may be allocated according to the number of remotes that are registered.
ber of slots that may be allocated according to the number of remotes that are registered.
CSMA_Predelay
- in CSMA mode, this parameter sets the maximum delay between the time a remote
senses a clear channel and it starts a transmission. Refer to Section 2.7.1 for more information.
CSMA_MaxBackoff
- in CSMA mode, this sets the maximum length of time that a remote will back off for
after a failed transmit attempt. Refer to Section 2.7.1 for more information.
MaxPropDelay
- this is the maximum propagation delay that remotes and base will use in their slot timing
calculations, in units of 3.1 µs. This is used to pad the amount of time dedicated to the signup slot. In-
creasing this value will subtract slightly from the overall slot time available to remotes for sending data.
Note that the free-space round trip propagation delay for one mile is 10.72 µs. Each increment of Max-
PropDelay thus corresponds to a maximum radius from the remote to the base of 0.29 mi (0.46 km).
creasing this value will subtract slightly from the overall slot time available to remotes for sending data.
Note that the free-space round trip propagation delay for one mile is 10.72 µs. Each increment of Max-
PropDelay thus corresponds to a maximum radius from the remote to the base of 0.29 mi (0.46 km).
EpochMode
- this is a base-only parameter that governs how the base will select an epoch number at
startup when it creates a network. In mode 0, the base will read the epoch number from NVRAM. In mode
1, it reads the value from NVRAM and increments it (and stores the result). In mode 2, it will generate a
random epoch number at every startup.
1, it reads the value from NVRAM and increments it (and stores the result). In mode 2, it will generate a
random epoch number at every startup.
4.2.3 Bank 2 - Status Registers
Size in
Bank
Loc'n
Name
R/W
bytes
Range
02
00
MacAddress
R
3
0..2
24
02
03
CurrNwkAddress
R
1
0..255
02
04
CurrNwkID
R
1
0..255
02
05
CurrRF_DataRate
R
1
0..4
02
06
CurrFreqBand
R
1
0.. 1
02
07
LinkStatus
R
1
0.. 1
02
08
RemoteSlotSize
R
1
0..243
02
09
TDMA_NumSlots
R
1
0..16
02
0A
Reserved
R
1
0..255
02
0B
TDMA_CurrSlot
R
1
0..16
02
0C
HardwareVersion
R
1
0..255
02
0D
FirmwareVersion
R
1
0..255
02
0E
FirmwareBuildNum
R
2
0..2
16
02
10
Epoch
R
1
0..255
02
11
SuperframeCount
R
1
0..255
02
12
RSSI_Idle
R
1
0..255
02
13
RSSI_Last
R
1
0..255
02
14
CurrTxPower
R
1
0..255
02
15
CurrAttemptLimit
R
1
0..255
02
16
CurrRangeDelay
R
1
0..255
Default
fixed value
as set as set
as set as set
current status
as
as set as set
as set as set
current status
as
set
as
set
reserved
current slot
0x00 = DNT900 rev A
current firmware load
current firmware load
as set
current value
as set
as set
as set
as set
as set
current slot
0x00 = DNT900 rev A
current firmware load
current firmware load
as set
current value
as set
as set
as set
as set
as set