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Technical s1.678.684.2000 

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©2009-2010 by RF Monolithics, Inc. 

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DNT900 - 08/16/10 

7.0  Troubleshooting 

 
DNT900 not responding - make sure SLEEP/DTR is not asserted (logic low) to bring the radio out of 
sleep mode. 
 
Can not enter protocol mode - make sure the host data rate is correct. The DNT900 defaults to 9.6 kb/s. If 
using the EnterProtocolMode command, send the complete protocol format for this command. 
 
A remote never detects carrier (DCD) - check that the base is running, and that the remote InitialNwkID 
parameter is the same as the base, or is set to 0xFF. If a remote is operating near the base (less than 6 ft 
or 2 m), be sure the transmitter power setting on both the base and remote is set to 1 mW. If the remote is 
operating far from the base, be sure the transmitter power setting on the base and remote is adequate for 
communication. Also make sure that the security keys are the same. 
 
Carrier is detected, but no data appears to be received - make sure that RTS is asserted to enable re-
ceive character flow. Make sure the RF transmit power is not on a high settings if the nodes are close 
together. 
 
Range is extremely limited - this is usually a sign of a poor antenna connection or the wrong antenna. 
Check that the antenna is firmly connected. If possible, remove any obstructions near the antenna. 
 
Transmitting terminal flashes (drops) CTS occasionally - this indicates that the transmit buffer is filling up. 
This most often is caused by using a higher serial port data rate than RF data rate. Adjusting the protocol 
parameters may increase the network efficiency. 
 

7.1  Diagnostic Port Commands 

 
FSTAT <option> - enables a frequency-ordered channel activity status log. 
 
Available options are: 
 
    0 - off 
    1 - on 
 
For either a base or remote, FSTAT shows the DataTx (data packet transmitted), AckRx (ACK received) 
and RegRx (registration or renewal request or reply received) activity status on each frequency with 
ASCII characters as follows: 
 
    ‘.’ (0x2E) - no activity 
    ‘1’ (0x31) - DataTx activity only 
    ‘2’ (0x32) - AckRx activity only 
    ‘3’ (0x33) - DataTx and AckRx activity 
    ‘4’ (0x34) - RegRx activity only 
    ‘5’ (0x35) - DataTx and RegRx activity 
    ‘6’ (0x36) - AckRx and RegRx activity 
    ‘7’ (0x37) - DataTx, AckRx and RegRx activity 

Summary of Contents for DNT900 Series

Page 1: ... RFM com Technical support 1 678 684 2000 Page 1 of 96 2009 2010 by RF Monolithics Inc E mail tech_sup rfm com DNT900 08 16 10 DNT900 Series 900 MHz Spread Spectrum Wireless Transceivers Integration Guide ...

Page 2: ... of up to 5 1 dBi of gain or any Yagi of up to 6 1 dBi gain The antenna s used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co located or operating in conjunction with any other antenna or transmitter IC RSS 210 Detachable Antenna Gain Restriction This device has been designed to operate with the antennas listed below an...

Page 3: ... Communications 12 2 10 Channel Access 12 2 10 1 Polling Mode 13 2 10 2 CSMA Mode 14 2 10 3 TDMA Modes 15 2 11 Point to Point and Point to Multipoint Networks 15 2 11 1 TDMA Throughput 16 2 11 2 Polling Throughput 16 2 11 3 CSMA Throughput 17 2 11 4 Latency 18 2 11 5 Configuration Validation 18 2 12 Tree Routing Systems 20 2 12 1 Example Tree Routing System 20 2 12 2 Tree Routing System Networks 2...

Page 4: ...ing Active Router ID Table 58 4 2 10 Bank 9 Registered MAC Addresses 58 4 2 11 Bank FF Special Functions 59 4 2 12 Protocol Mode Configuration Message Example 60 4 2 13 Protocol Mode Sensor Message Example 60 4 2 14 Protocol Mode Event Message Example 61 5 0 DNT900DK Developer s Kit 62 5 1 DNT900DK Kit Contents 62 5 2 Additional Items Needed 62 5 3 Developer s Kit Operational Notes 62 5 4 Develope...

Page 5: ...0 or 1000 mW transmit power with a firmware interlock of 85 mW maximum for 500 kb s operation Transparent ARQ protocol with data buffering ensures data integrity Simple interface handles both data and control at up to 460 8 kb s on the serial port or 80 64 kb s on the SPI port Analog and Digital I O simplifies wireless sensing Auto reporting mode for I O simplifies appli cation development 1 1 Why...

Page 6: ...rect sequence spread spectrum is produced by multiplying the transmitted data stream by a much faster noise like repeating pattern The ratio by which this modulating pattern exceeds the bit rate of the base band data is called the processing gain and is equal to the amount of rejection the system affords against narrow band interference from multipath and jammers Transmitting the data signal as us...

Page 7: ...se other implementation factors such as size cost power consumption and ease of implementation must also be considered before a final radio design choice can be made DNT900 series modules achieve regulatory certification under FHSS rules at air data rates of 38 4 115 2 and 200 kb s At 500 kb s the DNT900 series modules achieve regulatory certification under digital modulation or DTS DSSS rules At ...

Page 8: ...e RemoteLeave to keep track of remotes that have not yet been serviced allowing networks of more than 126 remotes to be indirectly tracked by the base 2 2 Authentication In many applications it is desirable to control which radios can join a network This provides security from rogue radios joining the network and simplifies network segregation for co located networks Registration is controlled by ...

Page 9: ...t Pin 18 is switched from logic low to high or an ExitProtocolMode command is sent to the primary serial input the DNT900 will switch to transparent operation Note that it is possible that part of the EnterProtocolMode command will be sent over the air as transparent data When operating in transparent mode two configuration parameters control when a DNT900 radio will send the data in its transmit ...

Page 10: ...mode broadcast packets are repeated a fixed number of times based on the value of the ARQ_AttemptLimit parameter In ARQ mode a packet is sent and an acknowledgement is expected on the next hop If an acknowledgement is not received the packet is transmitted again on the next available hop until either an ACK is received or the maximum number of attempts is exhausted If the ARQ_AttemptLimit paramete...

Page 11: ...wledgment is received the base will retransmit the same data on the next hop Note that acknowledgements from remotes are suppressed on broadcast packets from the base In point to point operation by default a remote will send the data in its transmit buffer on each hop up to the limit controlled by its RemoteSlotSize parameter If desired the MinPacketLength and TxTimeout parameters can be set above...

Page 12: ...ree routing systems are well suited to many industrial commercial and agricultural data acquisition applications Tree routing operation is supported by CSMA mode 1 channel access See Section 2 12 below 2 9 Full Duplex Serial Data Communications From a host application s perspective DNT900 serial communications appear full duplex Both the base host application and each remote router host applicatio...

Page 13: ...ote will attempt to transmit data at a time usually in response to a command from the base Polling mode 0 is a special case of CSMA mode 1 The user can set the BaseSlotSize and CSMA_ RemtSlotSize parameters when using this mode Since only one remote will attempt to transmit at a time to minimize latency the CSMA_Predelay and CSMA_Backoff parameters are not used Lease renewals are also not used aga...

Page 14: ...e sure that all the remotes do not transmit immediately after the base finishes transmitting CSMA mode 1 provides classical CSMA channel access and gives the user control over both the CSMA_Predelay and CSMA_Backoff parameters This mode is well suited for large numbers of uncoordi nated radios where periodic event reporting is used or tree routing operation is required In addition to CSMA_ Predela...

Page 15: ...e linked with the base even when fewer remotes routers are actually linked In this mode the remote slot sizes are constant TDMA with PTT mode 4 supports remotes with a push to talk feature also referred to as listen mostly remotes This mode uses fixed slot allocations Remotes can be registered for all but the last slot The last slot is reserved for the group of remotes that are usually listening b...

Page 16: ...he data to be sent but the Calculator has a mode to take this into account 2 11 2 Polling Throughput In polling mode the application sends data from the base to a specific remote which causes the remote and or its host to send data back to the application The network operates like a point to point network in this case In polling the HopDuration should be set just long enough to accommodate a base ...

Page 17: ...next hop at all To allow multiple remotes a chance to transmit on the same hop the HopDuration parameter must be set long enough to support the BaseSlotSize plus the number of remotes to transmit per hop multiplied by the CSMA_ RemtSlotSize plus the number of remotes to transmit per hop multiplied by the CSMA_Backoff Because of the way CSMA channel access works this does not guarantee that the des...

Page 18: ...s busy Again this is why CSMA networks are best used when there are a large number of nodes that send data infrequently The other factor impacting latency is retries This impact is not unique to frequency hopping radios but is common among all wireless technologies A radio only transmits data once per hop It needs to wait until the next hop to see if the transmission was received at the destinatio...

Page 19: ...ault as inputs to the Calculator program to determine minimum valid HopDuration CSMA contention mode 1 the same procedure as for polling is used except that the CSMA_ RemtSlotSize typically should be set at three times the maximum number of data bytes for point to multipoint networks The default values for CSMA pre delay and back off are assumed TDMA dynamic mode 2 this is the DNT900 s default ope...

Page 20: ... latency Tree routing systems are well suited to many industrial commercial and agricultural applications Compared to other DNT900 network configurations however tree routing systems require somewhat more initial planning and commissioning steps as discussed in this Section 2 12 1 Example Tree Routing System An example tree routing system is shown in Figure 2 12 1 1 In this example seven sensor lo...

Page 21: ...report function of the DNT900 radio can be used to send data through the tree on a timer or interrupt basis To set up the example system all of the DNT900s including the base must be configured with the same tree routing ID and have tree routing option enabled In addition R2 R5 and R6 must be assigned individual BaseModeNetID parameters and then configured for router operation The network IDs and ...

Page 22: ...ee routing system consists of one base and up to 63 routers where the base and each router can forward messages to from a total of 126 child radios leases enabled 1 A child radio can be either a remote or router within the system limitation of 63 routers total Within a DNT900 tree routing system a network refers to a group of radios communicating with a router or base acting as a parent and all of...

Page 23: ...D of 0x00 and NwkAddr of 0x00 When a radio is configured as a router it automatically assumes a NwkAddr of 0x00 The router s NwkID byte is held in its BaseModeNetID parameter and will have value in the range of 0x01 to 0x3F The BaseModeNetID parameter must be manually set in all routers As discussed below when a router s addressing is totally manually configured the remote mode NwkAddr network add...

Page 24: ...hild router from attempting to link with another parent in case its parent router fails The parent address of each router is known before the system becomes organized and heartbeat status messages and or Discover commands can be used to log the system addresses against the MAC addresses of each remote in the system Manual router parent and remote address assignment allows all radios addressing to ...

Page 25: ...uter R6 to Remote R7 1 Remote R7 Reply Turn Around 1 Remote R7 to Router R6 1 Router R6 to Router R5 1 Router R5 to Base 1 Base Turn Around 1 Base to Router R2 1 Router R2 to Remote R1 1 Total 13 Table 2 12 4 2 The minimum number of hops required is 13 so the minimum P2PReplyTimeout parameter value would be 7 hop pairs This minimum value provides no tolerance for transmission retries Selecting a v...

Page 26: ...s configuration provided only occasional RF transmission errors occur Plan on an average serial port data flow of 90 of the calculated error free capacity for general purpose applications The DNT900 transmit and receive buffers hold at least 1024 bytes and will accept brief bursts of data at high baud rates provided the average serial port data flow such as shown in the example above is not exceed...

Page 27: ...sage into the DNT900 if HOST_CTS switches high part way through the message as shown in Figure 2 14 2 but must then stop sending transmit message bytes until the DNT900 resets HOST_CTS to a logic low state If the DNT900 slave is holding a received message s when the SPI master clocks in a message to transmit received message bits will be simultaneously clocked out on the MISO line while the messag...

Page 28: ...is always protocol formatted Following the null bytes the 0xFB start of message symbol will then be clocked out followed by the message length byte The length byte can be used to confirm that all the bytes in each received message have been clocked out If a DNT900 slave is holding more than one received message the SPI_RX_AVL flag will remain high until all messages have been completely clocked ou...

Page 29: ...ep modes Hardware sleep mode is entered by switching SLEEP DTR Pin 11 on the DNT900 from logic low to high While in hardware sleep mode the DNT900 consumes less than 50 µA at room temperature This mode allows a DNT900 to be powered off while its host device remains powered After leaving hardware sleep mode Pin 11 low to high the radio must re synchronize with the base and re register Note that sle...

Page 30: ...eases are disabled If these settings are not used there is no guarantee that the remotes will be able to communi cate reliably Because leases are not supported there is no built in mechanism for the base to detect or announce to its host if a remote leaves the network To summarize while a remote is awake the following list of condition checks are used to determine if and when it is allowed to go b...

Page 31: ... link to an unencrypted base A remote s encryption key must match that of the base before it can link The EncryptionKey register can be set over the air so it can be changed periodically if desired Once an encryption key has been entered it can be changed but it cannot be read back 2 17 Synchronizing Co located Bases The EX_SYNC input Pin 15 on the DNT900 allows co located bases to synchronize the...

Page 32: ...umber of select able hopping patterns including patterns compatible with frequency allocations in the US Canada South America Israel Australia and New Zealand The DNT900 has six selectable RF output power levels 1 10 100 250 and 500 mW plus 1 W Also there are four selectable RF transmission rates 38 4 115 2 200 and 500 kb s The DNT900 includes a low noise preamplifier protected by two SAW filters ...

Page 33: ...DMA 16 CSMA unlimited ADC Input Range 0 3 3 V ADC Input Resolution 10 bits Signal Source Impedance for ADC Reading 10 KΩ PWM DAC Output Range 0 3 3 V PWM DAC Output Resolution 8 bits PWM Output Period 20 µs Primary and Diagnostic Serial Port Baud Rates 1 2 2 4 4 8 9 6 19 2 28 8 38 4 57 6 76 8 115 2 230 4 460 8 kb s Serial Peripheral Interface Data Rate 6 35 80 64 kb s Digital I O Logic Low Input L...

Page 34: ... 1st order 159 Hz 3 dB BW 11 SLEEP DTR I Default functionality is active high module sleep input active low DTR When switched low after sleep the module executes a power on reset Usually connected to host DTR 12 ADC2 I 10 bit ADC input 0 Full scale reading is referenced to the ADC_REF input 13 ADC1 I 10 bit ADC input 1 Full scale reading is referenced to the ADC_REF input 14 ADC0 I 10 bit ADC inpu...

Page 35: ...perating as a master and an input when it is operating as a slave 36 MOSI I O SPI master out slave in function This pin is an output when the DNT900 is operating as a master and is an input when the DNT900 is operating as a slave 37 MISO I O SPI master in slave out function This pin is an input when the DNT900 is operating as a master and is an output when the DNT900 is operating as a slave 38 SCL...

Page 36: ...side the range given above can cause damage and or create a fire and safety hazard Further care must be taken so logic inputs applied to the radio stay within the voltage range of 0 to 3 3 V Signals applied to the analog inputs must be in the range of 0 to ADC_REF Pad Pin 3 Applying a voltage to a logic or analog input outside of its operating range can damage the DNT900 module 3 5 ESD and Transie...

Page 37: ...ttenuation to avoid com promising antenna performance where antennas are internal to the enclosure Metal enclosures are not suitable for use with internal antennas as they will block antenna radiation and reception Outdoor enclo sures must be water tight such as a NEMA 4X enclosure 3 9 Labeling and Notices DNT900 FCC Certification The DNT900 hardware has been certified for operation under FCC Part...

Page 38: ...may not cause interference and 2 this device must accept any interference including interference that may cause undesired operation of the device ICES 003 This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus as set out in the radio interference regulations of Industry Canada Le present appareil numerique n emet pas de bruits radioelectriques de...

Page 39: ...ts vary in size and number depending on the type of message and whether it is a message sent from the host or is a reply from the radio see Table 4 1 2 1 below Messages that are generated on the serial interface by the user are referred to as host messages Messages that are generated by the radio are referred to as reply messages For many message types there is a reply message that corresponds to ...

Page 40: ... Data 0x27 Announce from Radio AnnStatus additional fields 0x28 RxEvent from Radio Addr RSSI Reg Bank Span Val 0x0A GetRemoteRegister from Host Addr Reg Bank Span 0x1A GetRemoteRegisterReply from Radio If command successful TxStatus Addr RSSI Reg Bank Span Val If command failed TxStatus Addr 0x0B SetRemoteRegister from Host Addr Reg Bank Span Val 0x1B SetRemoteRegisterReply from Radio TxStatus Add...

Page 41: ... RSSI because packet was routed NwkID Network identifier of network joined 1 byte BaseMacAddr MAC address of base that the remote joined 3 bytes AnnStatus Status announcement 1 byte Additional fields are also reported depending on the status code Status code Additional fields 0xA0 Radio has completed startup initialization none 0xA2 Base a child has joined the network MacAddr Reserved Range 0xA3 R...

Page 42: ...de command The input to the CFG pin is de bounced to make it compatible with a mechanical switch or jumper 4 1 4 Flow Control There are two flow control signals between the radio and the host HOST_RTS and HOST_CTS See Section 2 12 for flow control details 4 1 5 Protocol Mode Data Message Example In this example ASCII text Hello World is sent from the base to a remote using a TxData command The MAC...

Page 43: ...de R W 1 0 3 0 Remote 1 Base 2 PTT Remote 3 Router 0x00 0x01 RF_DataRate R W 1 0 4 0 500 1 200 2 115 2 3 38 4 kb s 0XFF auto 0x00 0x02 HopDuration R W 2 80 4000 10 ms 0x00C8 0x00 0x04 InitialParentNwkID R W 1 0 63 255 0xFF join any network 0x00 0x05 SecurityKey R W 16 0 2128 1 all null bytes 0x00 security disabled 0x00 0x15 SleepMode R W 1 0 1 0 off 1 on 0x00 0x16 WakeResponseTime R W 1 0 255 0x05...

Page 44: ... router or a remote to join with only the base Setting this parameter to the NwkID of a parent router forces a child router or a remote to join only this parent s network Setting this parameter to 0xFF in a router or remote allows them to join with any parent In a tree routing system the InitialParentNwkID parameter also determines the hopping pattern for the parent and children of each network Wh...

Page 45: ... 1000 mW 1 W Setting bit 4 to a 1 overrides automatic transmit power control and locks the transmit power at the set level except when the data rate is set to 500 kb s At this data rate the firmware always limits the transmit power to a maximum of 19 dBm 85 mW to comply with FCC regulations ExtSyncEnable this parameter enables or disables the hardware EX_SYNC function on Pin 15 When enabled a puls...

Page 46: ...0 seconds If the heartbeat interval is set to 0x0000 remote heartbeats are disabled Since router heartbeats are needed to maintain the system routing table setting the HeartbeatIntrvl value on a router to 0x0000 will cause heartbeats to be sent at the default 20 second rate Setting the HeartbeatIntrvl parameter to 0xFFFF will suppress heartbeats except during registration or when an error is detec...

Page 47: ...Hz and Israel Australia New Zealand 915 to 928 MHz AccessMode this sets the channel access mode that remotes will use to communicate with the base Access Mode Description Max of Remotes Remote Slot Size 0 Polling unlimited manual 1 CSMA unlimited manual 2 default TDMA dynamic slots up to 16 automatic 3 TDMA fixed slots up to 16 automatic 4 TDMA with PTT up to 16 automatic BaseSlotSize This paramet...

Page 48: ...gis tration slot Increasing 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 incre ment of MaxPropDelay thus corresponds to a maximum radius from the remote to the base of 0 29 mi 0 46 km The default setting provides enough time to handle remotes up to 20 miles away...

Page 49: ...ng and the P2PReplyTimeout pa rameter setting If the heartbeat interval in seconds is less than the P2PReplyTimeout in hop pairs it is possible that a router will not repeat an un ACKed heartbeat packet quickly enough to prevent the base from timing that router out heartbeats are repeated only when an ACK is not received within the P2PReplyTimeout interval Thus setting the P2PReplyTimeout to a ver...

Page 50: ...ead bytes must be less than or equal to this value or the packet will be discarded In the three TDMA modes the remote slot size is automatically computed and this value is read only In polling and CSMA modes the remote slot size must be set by the user The parameter to set this is CSMA_RemtSlotSize in Bank 1 TDMA_NumSlots in TDMA access modes this returns the number of slots currently allocated TD...

Page 51: ...Qual returns the number of transmission sent before and ACK is received multiplied by 4 4 2 4 Bank 3 Serial and SPI Settings Size in Bank Loc n Name R W bytes Range Default 0x03 0x00 SerialRate R W 2 1 384 0x0030 9 6 kb s 0x03 0x02 SerialParams R W 1 0 7 0x00 8N1 0x03 0x03 SerialControls R W 1 0 7 0X07 0x03 0x04 SPI_Mode R W 1 0 2 0x00 SPI disabled 0x03 0x05 SPI_Divisor R W 1 1 27 0x0A 80 64 kb s ...

Page 52: ... are enabled the primary serial UART port operation is disabled in SPI Slave mode and restricted in SPI Master mode The diagnostic serial port continues to operate normally Note that only protocol formatted messages can be used when a DNT900 is configured for SPI operation SPI_Mode has the following settings Setting Mode 0x00 SPI disabled serial UART mode default 0x01 SPI Slave mode 0x02 SPI Maste...

Page 53: ...o its Slave peripheral and transmit back the Slave s re sponse In either case the command string and response string are limited to 32 bytes Only data mes sages are routed through the DNT900 s SPI port in Master mode Command packets and command replies are routed through the primary serial port When configured as an SPI Master the DNT900 sets SS low one SPI bit period before the start of mes sage ...

Page 54: ...o it transparently without requiring the host to understand or conform to the DNT900 s built in protocol This setting is recommended for point to point applications for legacy applications such as wire replacements where another serial proto col may already exist Setting this parameter to 1 enables the DNT900 host protocol which is recom mended for point to multipoint applications and is preferred...

Page 55: ...seful for point to point networks where there are only two endpoints for instance in applications where a simple serial cable is being replaced MaxPktsPerHop this parameter sets a limit on the maximum number of packets a radio can send on each frequency hop The default value is 3 the range is 1 to 3 4 2 6 Bank 5 I O Peripheral Registers Size in Range Bank Loc n Name R W bytes in bits Default 0x05 ...

Page 56: ...sholdHi R W 2 10 0x03FF 0x06 0x19 IO_ReportTrigger R W 1 0 1 0x01 GPIO0 0x06 0x1A IO_ReportInterval R W 4 32 0x00000BB8 every 30 seconds 0x06 0x1E IO_ReportPreDel R W 1 8 0x00 0x06 0x1F IO_ReportRepeat R W 1 8 0x01 GPIO_Dir this parameter is a bitmask that sets whether the GPIOs are inputs 0 or outputs 1 The default is all inputs GPIO_Init this parameter is a bitmask that sets the initial value fo...

Page 57: ...ial break condition can be eliminated by setting bit 6 high but sleep current will be increased PWM0_Init this parameter sets the initial value for PWM0 at startup PWM1_Init this parameter sets the initial value for PWM1 at startup ADC_SampleIntvl this parameter sets the interval between the beginning of one ADC read cycle and the next ADC read cycle The three ADC inputs are read on each ADC read ...

Page 58: ...ovedAddr9 R W 3 0x07 0x1E ApprovedAddr10 R W 3 0x07 0x21 ApprovedAddr11 R W 3 0x07 0x24 ApprovedAddr12 R W 3 0x07 0x27 ApprovedAddr13 R W 3 0x07 0x2A ApprovedAddr14 R W 3 0x07 0x2D ApprovedAddr15 R W 3 ApprovedAdd0 15 the three byte parameters in Bank 7 are the MAC addresses of the remotes author ized to join the network The addresses are entered in little endian format such that a radio with MAC ...

Page 59: ...f 0x00 to this location forces a software reset of the microcontroller This will enable those changes which require a reset If this is written to before 0x01 is written to the MemorySave parameter the last parameter values saved before the reset will be in effect A reply packet either local or over the air may not be received when writing a value to this register Writing 0x5A to this location will...

Page 60: ...tRegisterReply message as follows 0xFB 0x01 0x14 In order for this new RF power setting to persist through a base power down MemorySave must be invoked This is done by setting a one byte parameter in register 0xFF of bank 0xFF to 0x01 with another SetRegister command 0xFB 0x05 0x04 0xFF 0xFF 0x01 0x01 The base will write the current parameter values to EEPROM and return a SetRegisterReply message ...

Page 61: ... set the periodic report timer bit in IO_ReportTrigger to is 0xFB 0x08 0x0B 0x56 0x34 0x12 0x19 0x06 0x01 0x10 The periodic report timer bit in IO_ReportTrigger is located in bit position four 00010000b or 0x10 The IO_ReportTrigger parameter is updated and SetRemoteRegisterReply is returned 0xFB 0x06 0x1B 0x00 0x56 0x34 0x12 0xC4 The remote will start sending event messages on 10 second intervals ...

Page 62: ...ble assembly two A B USB cables One DNT900DK documentation and software CD 5 2 Additional Items Needed To operate the kit the following additional item is needed One PC with Microsoft Windows XP or Vista Operating System The PC must be equipped with a USB port or a serial port capable of operation at 9 6 kb s 5 3 Developer s Kit Operational Notes DNT900DK kits are preconfigured to run at a 500 kb ...

Page 63: ...lt RF power setting is 0 dBm 1 mW which is suitable for operation at a spacing of about 2 m 6 ft The RF power level should be set higher as needed for longer range operation Note that setting the RF power to a high level when doing testing at 2 m can overload the DNT900P receiver and cause erratic operation See Section 5 3 5 5 Developer s Kit Hardware Assembly Observe ESD precautions when handling...

Page 64: ...RF Monolithics Inc E mail tech_sup rfm com DNT900 08 16 10 As shown in Figure 5 5 3 confirm there is a jumper on pins J14 Note this jumper can be removed and a current meter connected across J14 to measure just the DNT900 s current consumption during operation Figure 5 5 3 ...

Page 65: ... switches operation from the RJ 45 connector The USB interface is based on an FT232RL serial to USB converter IC manufactured by FTDI The FT232RL driver files are located in the i386 and AMD64 folders on the kit CD and the latest version of the drivers can downloaded from the FTDI website www ftdichip com The drivers create a virtual COM port on the PC Power the Base using one of the supplied wall...

Page 66: ...rt The preferred PC interface is a serial port capable of operating at 9 6 kb s or faster As discussed above the USB interface can also be used Connect the Base to the PC and power up the Base and the Remote development boards using the wall plug power supplies The DNT Demo utility program is located in the PC Programs folder The DNT Demo requires no installation and can be simply copied to the PC...

Page 67: ...se either the hardware port or the USB virtual serial port Then click OK to activate the serial connection Figure 5 6 1 2 At this point the Demo will collect data from the Base filling in data in the Local Radio column on the Demo window as shown in Figure 5 6 1 3 The Status Window should also show that the Remote has joined the Base Click on the drop down box at the top of the Radio 1 column and ...

Page 68: ...1 4 To perform serial data loop back testing with the kit move the two jumpers on the Remote board labeled Ext_TX and Ext_RX to connect the center and right header pins This disconnects the module s TX and RX pins from the USB and RS 232C circuits Use a banana clip or other short jumper to connect together the two pins on the header labeled Ext_MICRO See Figure 5 6 1 5 Attempting loop back testing...

Page 69: ...The E mail address is tech_sup rfm com 5 6 2 Serial Communication and Radio Configuration Connect PCs to both the Base and the Remote for serial communication testing Click the Stop button under the Refresh Delay label on the I O Tools tab and move to the Transmit Tools tab as shown in Figure 5 6 2 1 Figure 5 6 2 1 Pressing the Transmit button on this screen sends the message in the Data to Transm...

Page 70: ...abs corresponding to Bank 8 and the data on the last tab corresponding to Bank 9 Figure 5 6 2 2 The Transceiver Setup Tab is shown in Figure 5 6 2 2 and corresponds to Bank 0 The current values of each Bank 0 parameter are displayed and can be updated by selecting from the drop down menus or entering data from the keyboard and then pressing the Apply Changes button Note that data is displayed and ...

Page 71: ...t Bank 1 holds configuration parameters for the base only except for ARQ_Mode which applies to both the base and the remotes Figure 5 6 2 4 Figure 5 6 2 4 shows the Status tab contents corresponding to Bank 2 Note the Status tab contains read only parameters Figure 5 6 2 5 Figure 5 6 2 5 shows the Serial tab contents corresponding to Bank 3 The values shown are the defaults for serial port operati...

Page 72: ...corresponding to Bank 4 Transparent data serial com munication is currently chosen Figure 5 6 2 7 Figure 5 6 2 7 shows the I O Peripherals tab contents corresponding to Bank 5 GPIO ports 1 and 3 are logic high GPIO ports 0 2 4 and 5 are logic low The 10 bit ADC input readings and PWM output set tings are given in Big Endian byte order Event flags are presented on the right side of the window ...

Page 73: ... can be set for them with check boxes The type of interrupt trigger is selected from the drop down boxes to the right of the check boxes GPIO alternate function periodic I O reporting reporting interval and enable disable sleep I O states can also be specified under this tab Figure 5 6 2 9 Figure 5 6 2 9 shows the second I O Setup tab contents corresponding to Bank 6 ADC input and PWM output param...

Page 74: ...zed to join the network in AuthMode 1 are input into Bank 7 Figure 5 6 2 11 Figure 5 6 2 11 shows the first Routing Table tab which displays part of the contents of Bank 8 This bank contains the tree routing active router ID table which is maintained by a base for its system It describes the organization of all active routers in the system This table is used by the base and the routers to determin...

Page 75: ...3 Figure 5 6 2 13 shows the Registered tab which displays the first seven parameters in Bank 9 This bank holds the MAC addresses of all radios registered to a base or router Up to 126 MAC addresses can be registered Each bank parameter can hold up to five MAC addresses with each MAC address containing three bytes Three byte segments in a parameter not holding a MAC address with hold a null address...

Page 76: ...s F1 toggles the SLEEP DTR input to the DNT900 on and off This allows the DNT900 to be reset F2 toggles the RTS input to the DNT900 on and off providing manual flow control F6 toggles test transmissions on and off The test message is This is a test The DNT Wizard also includes the ability to log messages to and from the DNT900 This feature is espe cially useful in confirming the format of protocol...

Page 77: ...2 Set the baud rate to 9600 9 6 kb s Set the CommPort to match the serial port connected to the Base either the hardware port or the USB virtual serial port Then click OK to activate the serial connection Figure 5 7 2 At this point the Wizard will collect data from the Base filling in data under Current Settings as shown in Figure 5 7 3 The Status Window should also show that the Remote has joined...

Page 78: ..._sup rfm com DNT900 08 16 10 There are three tabs on the DNT Wizard main window Receive Data Transmit Data and Wincom Figure 5 7 4 Received messages are displayed in the Receive Data tab along with the MAC address of the sender and the RSSI signal strength of the received message in dBm See Figure 5 7 4 ...

Page 79: ...Addr drop down box Note that the address for the base is always 0x000000 If the Transmit Interval is set to 0 the message is sent once each time the Transmit button is clicked When the Transmit Interval is set to an integer greater than zero the message will sent at the beginning of each interval until the Stop button was Transmit button is clicked The status of each transmission is shown below TX...

Page 80: ... RF Monolithics Inc E mail tech_sup rfm com DNT900 08 16 10 Figure 5 7 6 As shown in Figure 5 7 6 the Wincom tab provides the basic functionality of a serial terminal program Messages typed in are sent and messages received are appended to the bottom of the on screen text ...

Page 81: ...register Banks 0 through 5 as discussed in Section 4 2 above with the data on the next two tabs corresponding to configuration register Bank 6 the data on the next tab corresponding to Bank 7 the data on the following two tabs corresponding to Bank 8 and the data on the last tab corresponding to Bank 9 Figure 5 7 7 The Configuration window in the DNT Wizard is identical the Configuration window in...

Page 82: ...le View and Tools menus are shown in Figure 5 7 8 Figure 5 7 8 The Tools menu contains two very useful items Packet Builder opens the window shown in Figure 5 7 9 On the left the Packet Type drop down box provides a selection of all packet types used in the DNT900 protocol On the right the reply packet types are presented Figure 5 7 9 Figure 5 7 10 ...

Page 83: ...ter Reply Sent Data FB 04 03 00 03 04 Get Register Recv Data FB 08 13 00 03 04 04 00 00 07 Get Register Reply Sent Data FB 04 03 00 04 08 Get Register Recv Data FB 0C 13 00 04 08 00 05 05 01 07 00 02 00 Get Register Reply Sent Data FB 04 03 00 05 12 Get Register Recv Data FB 16 13 00 05 12 01 00 00 00 01 01 F5 01 FD 01 DA 01 00 00 00 00 00 00 Get Register Reply Sent Data FB 04 03 00 06 1E Get Regi...

Page 84: ...ED D4 illuminates on the base when one or more remotes are registered to it unless the base has been configured to assert DCD on power up In this case it will be on as long as the dev board is powered Green Activity LED D1 illuminates when transmitting or receiving RF data Red Receive LED D3 illuminates when sending received data through the serial port to the PC Green Trans mit LED D2 illuminates...

Page 85: ...nd RADIO_RXD pins to the respective serial data lines on the evaluation board It is possi ble to connect directly to RADIO_TXD and RADIO_RXD by moving the jumpers over In this case J11 1 is the input for transmitted data and J11 2 is the output for received data Note this a 3 V logic interface The DNT900 has its own boot loader utility that allows the protocol firmware to be installed with a termi...

Page 86: ...the silkscreen The wiper of pot R10 drives the input of ADC1 Clockwise rotation of the pot wiper increases the voltage Thermistor RT1 is part of a voltage divider that drives ADC0 LED D5 illumi nates when GPIO1 is set as a logic high output LED D10 illuminates when GPIO3 is set as a logic high The DNT900P interface board includes a 5 V regulator to regulate the input from the 9 V wall plug power s...

Page 87: ...o program installed 3 Place the transceiver interface boards at least six feet two meters apart 4 Start the DNT Demo program 5 Click the Connect button on the Demo window This will open a serial port setup dialog box Set the baud rate to 9600 9 6 kb s and select the COM port where the Base is connected 6 At this point the Demo will collect data from the Base filling in data in the Local Radio colu...

Page 88: ...e that RTS is asserted to enable re ceive character flow Make sure the RF transmit power is not on a high settings if the nodes are close together Range is extremely limited this is usually a sign of a poor antenna connection or the wrong antenna Check that the antenna is firmly connected If possible remove any obstructions near the antenna Transmitting terminal flashes drops CTS occasionally this...

Page 89: ... rolls over to 0x000 after count 0xCE5 The content of the seven data values are detailed below ASCII representations of the hexadecimal value of each byte are output separated by space characters Byte 0 current channel 0 to 49 frequency is 902 75 MHz current channel 0 5 MHz Byte 1 same data as FSTAT 1 except no activity is 0x30 Byte 2 RSSI_Last RSSI of last RF packet received in dBm 8 bit signed v...

Page 90: ...imal Byte 1 0x01 is the same status data as FSTAT data above In this case DataTx activity only Byte 2 0xDA is the last RSSI value 38 dBm Byte 3 0x98 is the RSSI idle value 100 dBm Byte 4 0x00 is the range delay estimate remote only The remote is very close to the base Byte 5 0x01 provides the serial port status HOST_CTS is high Byte 6 0x01 provides the communication status DataTx active only Note ...

Page 91: ...ch_sup rfm com DNT900 08 16 10 8 0 Appendices 8 1 Ordering Information DNT900C transceiver module for solder pad mounting DNT900P transceiver module for pin socket mounting 8 2 Technical Support For DNT900 technical support call RFM at 678 684 2000 between the hours of 8 30 AM and 5 30 PM Eastern Time ...

Page 92: ... O u t l i n e a n d M o u n t i n g D i m e n s i o n s D i m e n s i o n s i n i n c h e s a n d m m 2 0 5 0 5 2 0 7 1 3 4 0 3 4 0 4 0 6 3 0 1 6 0 0 0 1 7 0 4 3 2 0 0 5 0 1 2 7 0 0 4 0 1 0 2 0 1 0 0 2 5 4 1 4 0 0 1 0 0 2 5 4 Figure 8 3 1 0 1 1 0 2 7 9 0 0 7 0 1 7 8 0 1 0 0 2 5 4 1 1 8 0 2 9 9 7 D N T 9 0 0 C P C B F o o t p r i n t D i m e n s i o n s i n i n c h e s a n d m m 1 4 0 Figure 8 3 2...

Page 93: ...4 0 0 4 0 1 0 2 0 1 0 0 2 5 4 0 3 3 3 8 4 6 0 0 5 0 1 2 7 1 3 6 0 3 4 5 4 1 4 0 1 2 6 0 3 2 0 0 0 0 5 0 1 2 7 Figure 8 3 3 1 9 0 4 8 2 6 2 0 0 5 0 8 0 0 1 0 2 5 4 D N T 9 0 0 P I n t e r f a c e C o n n e c t o r P C B L a y o u t D e t a i l 0 1 0 2 5 4 C o n n e c t o r s a r e F C I E l e c t r o n i c s 7 5 9 1 5 4 2 0 L F o r e q u i v a l e n t D i m e n s i o n s i n i n c h e s a n d m m 1...

Page 94: ...DNT900 Development Board Schematic 0 1 2 3 334 5 6 7 6 89 9 3 0 1 2 3 334 5 6 7 6 89 9 3 0 1 2 3 334 5 6 7 6 89 9 3 0 110 2 1 110 3 110 4 5 4 5 5 4 5 5 4 5 5 5 5 3 4 5 3 4 5 3 3 5 4 4 3 4 4 4 5 5 4 5 5 5 5 5 3 3 5 4 4 3 4 3 3 5 5 3 3 4 3 7 7 5 5 5 5 54 54 4 5 3 3 4 4 6 7 6 7 4 5 4 5 4 3 5 4 3 5 4 4 4 5 3 4 3 5 3 4 4 4 4 4 5 4 3 4 4 54 54 6 7 8 5 6 7 8 5 ...

Page 95: ...up rfm com DNT900 Integration Guide 08 16 10 0 1 2 3 334 5 A 6 7 6 89 9 3 0 1 2 3 334 5 A 6 7 6 89 9 3 0 1 2 3 334 5 A 6 7 6 89 9 3 9 2 2 2 0 110 2 1 110 3 110 1 4 4 4 4 4 7B 3 3 5 5 5 5 3 3 3 3 4 3 4 4 C C 4 3 4 3 5 5 5 5 7 7 5 5 4 4 5 5 5 5 4 3 5 4 6 4 6 3 5 6 3 5 6 4 4 4 4 3 3 3 3 4 3 5 3 3 5 5 4 4 5 5 ...

Page 96: ... are not de signed or by causes external to the goods such as but not limited to power failure No suit or action shall be brought against Seller more than twelve 12 months after the related cause of action has oc curred Buyer has not relied and shall not rely on any oral representation regarding the goods sold here under and any oral representation shall not bind Seller and shall not be a part of ...

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