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CL4790  

U

SER 

G

UIDE

 

V

ERSION 

3.0 

 

 

 

 

 

 

 

 

Americas: +1-800-492-2320 Option 2 
Europe: +44-1628-858-940 
Hong Kong: +852-2923-0610 
www.lairdtech.com/ramp  

 

Summary of Contents for CL4790

Page 1: ...CL4790 USER GUIDE VERSION 3 0 Americas 1 800 492 2320 Option 2 Europe 44 1628 858 940 Hong Kong 852 2923 0610 www lairdtech com ramp ...

Page 2: ... Installation Instructions WARNING To satisfy FCC RF exposure requirements for mobile transmitting devices this equipment must be professionally installed such that the end user is prevented from replacing the antenna with a non approved antenna The end user should also be prevented from being within 20cm of the antenna during normal use with the exception of hands feet wrists and ankles The prece...

Page 3: ...com ramp 3 CONN GUIDE_CL4790 REVISION HISTORY Version Date Changes 1 0 Initial Release 1 1 Changes and Revisions 2 0 02 Aug 2013 Major changes and revisions updated format and data 3 0 18 Dec 2013 Separated Hardware Integration Guide HIG from User Guide information created two separate documents Add Related Documents section ...

Page 4: ...ion History 3 Contents 4 CL4790 RF Transceiver 5 Overview 5 Features 5 Theory of Operation 6 RF Architecture 6 Network Topologies 6 Modes of Operation 6 Security 11 Spread Spectrum History 11 How Spread Spectrum Works 11 Frequency Hopping Spread Spectrum 11 CL4790 Security Features 11 Programming the CL4790 12 Appendix I Troubleshooting 14 Force 9600 Baud Recovery 14 ...

Page 5: ...eral transceiver pairs to carry on simultaneous conversations on the same network CL4790s implement a proprietary communication protocol to provide secure data transmissions Using FHSS technology ensures data reliability over long distances The CL4790 transceivers use the 900 MHz ISM license free frequency band which requires no additional certifications when designing into a new or legacy data sy...

Page 6: ...ransmit or Command mode when the OEM host sends data over the serial interface The contents of the data on the serial interface determine which of two modes the radio enters Transmit Mode All packets sent over the RF are either Addressed or Broadcast packets You may dynamically control Broadcast and Addressed delivery with the API Control byte which can be modified during operation with On the Fly...

Page 7: ...g data the transceivers update their Session Count every time data or an RF acknowledge is received The SLock0 and SLock1 settings control Session Count as shown below Table 1 Session Count Truth Table Case Slock0 Slock1 Transceiver Receiving an Addressed Packet Transceiver Receiving a Broadcast Packet 1 0 0 Radio loads its Current Session Count with its Session Count Refresh Radio loads its Curre...

Page 8: ...he remote radio s Session Count Refresh This is suitable for full duplex applications as the Session is extended as long as there is communication Note This is the default case with which the radio ships and may not work well for all applications Use Case 4 when a large number of data packets are lost during operation Case 4 In this case a radio loads its Session Count with the remote radio s curr...

Page 9: ...CL4790 User Guide Version 2 0 Americas 1 800 492 2320 Option 2 Europe 44 1628 858 940 Hong Kong 852 2923 0610 www lairdtech com ramp 9 CONN GUIDE_CL4790 Figure 1 Pending RF data in buffer flow ...

Page 10: ...CL4790 User Guide Version 2 0 Americas 1 800 492 2320 Option 2 Europe 44 1628 858 940 Hong Kong 852 2923 0610 www lairdtech com ramp 10 CONN GUIDE_CL4790 Figure 2 Pending RF data in buffer flow ...

Page 11: ...re harder to jam interfere with than narrowband signals and have a much lower probability of being intercepted which is why the military has used SS for so many years The spread of energy over a wide band makes SS signals less likely to interfere with narrowband communications Narrowband communications conversely cause little to no interference to SS systems because the receiver effectively integr...

Page 12: ... of the encrypted data who know the algorithm but do not have the correct key cannot derive the original data algorithmically However anyone who does have the key and algorithm can easily decrypt the encrypted data and obtain the original data A standard algorithm based on a secure key thus provides a basis for exchanging encrypted data by issuing the encryption key to those authorized to have the...

Page 13: ...point to multipoint based on the radio s current settings If the Destination Address field is set to any value other than FF FF FF FF FF FF the radio sends data only to the radio whose MAC matches that specified in the Destination Address field point to point If the Destination Address field is set to FF FF FF FF FF FF it is set to Broadcast mode and transmits to all transceivers in range with the...

Page 14: ...he correct COM port Check the COM port settings for correct baud rate parity and either Hardware or No Flow Control May be caused by Flow Control set to Xon Xoff Try increasing the Maximum Transmit Attempts clients and or Broadcast Attempts servers in small increments until communication is established Connect a Null Modem adapter between the client and its host device Check the Destination Addres...

Page 15: ...Handshaking Hardware Data Bits 8 Stop Bits 1 9 Under Options ensure the Read Write with AT Commands check box is selected 10 Ensure the Port Status is open 11 On the Configure tab click Read Radio 12 Set the Interface Baud Rate to the appropriate value and click Write Radio 13 Power off the radio 14 Remove the jumper 15 Power on the radio 16 Set the Baud Rate on the PC Settings tab to the baud rat...

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