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Page 48 of 80
DNT90 Integration Guide - 08/09/12
SpiOptions
- this parameter allows the SPI to be configured with the following options:
Setting
Option
0x00
Leading edge rising, sample leading edge, MSBs sent first
0x01
Leading edge rising, sample falling edge, MSBs sent first
0x02
Leading edge falling, sample leading edge, MSBs sent first
0x03
Leading edge falling, sample falling edge, MSBs sent first
0x04
Leading edge rising, sample leading edge, LSBs sent first
0x05
Leading edge rising, sample falling edge, LSBs sent first
0x06
Leading edge falling, sample leading edge, LSBs sent first
0x07
Leading edge falling, sample falling edge, LSBs sent first
SpiMasterCmdLen
- this parameter sets the length for the SPI master command string that will be used to
interrogate the slave peripheral, when SPI master mode is selected with periodic I/O reporting enabled.
SpiMasterCmdStr -
this parameter holds the SPI master command string that is used to interrogate the
slave peripheral when SPI master mode is selected and periodic I/O reporting is enabled.
7.4.5 Bank 0x04 - Host Protocol Settings
Bank
Location
Name
R/W
Size
Range
Default
0x04
0x00
ProtocolMode
R/W
0x01
0..1
0 (Transparent)
0x04
0x01
TxTimeout
R/W
0x01
0..255
0 (No timeout)
0x04
0x02
MinPacketLength
R/W
0x01
0..255
1 (byte)
0x04
0x03
TransPtToPtMode
R/W
0x01
0..1
1 (Last RX)
0x04
0x04
MsgsPerHop
R/W
0x01
1..8
8
Table 7.4.5.1
ProtocolMode
- this parameter selects the host protocol mode. The default is 0x00, which is transparent
mode, meaning the radio conveys whatever characters that are sent to it
transparently
, without requiring
the host to understand or conform to the DNT90E's built-in protocol. This setting is recommended for
point- to-point applications for legacy applications such as wire replacements where another serial
protocol may already exist. Setting this parameter to 0x01 enables the DNT90E protocol formatting. It is
not necessary to define the same protocol mode for all radios in a network. For example, it is frequently
useful to configure all the remotes for transparent mode and the base for protocol mode. Note that it is
possible for the host to switch the radio from transparent mode to protocol mode and back as required by
transmitting an
EnterProtocolMode
command.
TxTimeout
- this parameter is used to group transparent data to be sent in a single transmission rather
than being split over two hops. Messages sent over two hops can have gaps in the received data stream
that can cause problems for the receiving application - for example, Modbus RTU. This parameter is the
transmit timeout used for determining message boundaries in transparent data mode. Parameter units
are in milliseconds. A message boundary is determined whenever a gap between consecutive characters
is equal to or greater than the
TxTimeout
value, or the number of bytes reaches the
MinPacketLength
.
Either condition will trigger a transmission. The default
TxTimeout
value is 0 ms which will have the radio
send whatever data is in its transmit buffer as soon as possible.
MinPacketLength
- this parameter is similar to
TxTimeout
except it uses the number of bytes received
instead of the amount of time without receiving a byte. The default is one byte. A transmission is triggered
when either the number of bytes reaches
MinPacketLength
or a gap is detected between consecutive