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AC4490 User Guide 

Version 4.5 

 

Laird Connectivity Solutions Support Center: 
http://ews-support.lairdtech.com 

www.lairdtech.com/ramp

 

35 

Americas: +1-800-492-2320 

Europe: +44-1628-858-940 

Hong Kong: +852 2923 0610

 

 

 

4.

 

All other Servers in the collocated system (servers that are being synchronized to the Hop Master server) 
should have Sync to Channel enabled. 

5.

 

All other servers in the collocated system should have their Sync Channel set to a value lower than their 
RF Channel Number.  

6.

 

All servers, including the Hop Master server, should have their RF Channel Numbers separated by a 
minimum of 4-5 Channels (i.e. Server 1, Hop Master = RF Ch 16, Server 2 = RF Ch 21, Server 3 = RF Ch 
26…) to avoid inter-channel interference between the radios as they hop through their pseudo-
random hopping sequence. 

7.

 

If the servers to be synchronized are in range of the Hop Master server, it is preferable that their Sync 
Channel be set to the RF Channel Number of the Hop Master server. 

8.

 

If some of the servers to be synchronized are outside of the range of the Hop Master server, their Sync 
Channel should be set to the RF Channel Number of a server (with a lower RF Channel Number than its 
own) that is in range of, and synchronized to, the Hop Master server. 

All collocated servers must be programmed to the same channel set. There are 32 available channels for the 
CL4490-1000, as shown in 

Table 8

. 

Table 8: RF Channels for  AC4490 
Channel Set 

RF Channel 
Number Range 
(0x40) 

Frequency Details & Regulatory 
Requirements 

Countries 

0 (AC4490 - 1x1 
AC4490 - 200) 

0x00 - 0x0F 

902 - 915 MHz (26 hop bins) 

US / Canada 

1 (AC4490 - 1x1 
AC4490-200 
AC4490 - 1000) 

0x10 - 0x2F 

902 - 928 MHz (50 hop bins) 

US / Canada 

2 (AC4490 - 1x1 
AC4490 – 200 
AC4490 - 1000) 

0x30 - 0x37 

915 - 928 MHz (22 hop bins) 

Australia (-1x1/-200/-1000) 

What happens if you don’t enable Sync to Channel and you have collocated servers? There are good odds 
that you will see a decrease in throughput due to the systems trying to occupy the same frequency at the 
same time. In severe cases, you could lose communications all together depending on how much bandwidth 
your system requires. Due to crystal differences between the servers, you may see intermittent interference. 

 

Figure 6: Two servers without Sync to Channel enabled 

Summary of Contents for AC4490

Page 1: ...AC4490 User Guide Version 4 5 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Embedded Wireless Solutions Support Center http ews support lairdtech com www lairdtech com ramp ...

Page 2: ...n and links to new website Sue White 4 5 18 May 2017 Removed references to EOL part numbers Jonathan Kaye FCC Notice WARNING This device complies with Part 15 of the FCC Rules Operation is subject to the following two conditions 1 This device may not cause harmful interference and 2 This device must accept any interference received including interference that may cause undesired operation RF Expos...

Page 3: ...4490 RF Transceiver 4 Overview 4 Features 4 Theory of Operation 5 RF Architecture 5 Modes of Operation 5 AC4490 Configuration 8 AT Commands 8 Command Descriptions 10 API Control 20 EEPROM Parameters 22 Appendix I API 29 Appendix II Sync to Channel 34 Sync to Channel What is it and do I need to use it 34 How do I configure Sync to Channel 36 I ve configured my radios what s next 42 Related Document...

Page 4: ...ceivers synchronized to it To establish synchronization between transceivers the server emits a beacon upon detecting a beacon an RF link is established and a GPIO is toggled to signify to the host that the link is active This document contains information about the hardware and software interface between a Laird AC4490 transceiver and an OEM Host Information includes the theory of operation speci...

Page 5: ... modes the transceiver enters Transmit Mode All packets sent over the RF are either Addressed or Broadcast packets Broadcast and Addressed delivery can be controlled dynamically with the API Control feature set which can be enabled in the EEPROM configuration To prohibit transceivers from receiving broadcast packets Unicast Only can be enabled Addressed Packets When sending an addressed packet the...

Page 6: ...ening for data While in Receive mode subsequent data of up to 80 bytes can be received every hop 20 ms Command Mode A radio enters Command mode when data is received over the serial interface from the OEM host and contains the AT Enter AT Command mode command or when the state of the CMD DATA pin is transitioned low Once in Command mode the radio interprets all data received as command data Comman...

Page 7: ...Version 4 5 Laird Connectivity Solutions Support Center http ews support lairdtech com www lairdtech com ramp 7 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 2 Pending Data in Buffer Flow ...

Page 8: ...and forward these to the OEM Host AT Command Mode While in CC Command mode using AT Commands the RF interface of the transceiver is active but packets sent from other transceivers will not be received The transceiver uses Interface Timeout RF Packet Size to determine when a CC Command is complete Therefore there should be no delay between each character as it is sent from the OEM Host to the trans...

Page 9: ...n bit1 Auto Channel bits 2 7 0 Read Digital Inputs 0xCC 0x20 0xCC bit 0 GI0 bit 1 GI1 Read ADC 0xCC 0x21 0x01 AD In 0x02 Temp 0x03 RSSI 0xCC MSB of 10 bit ADC LSB of 10 bit ADC Report Last Valid RSSI 0xCC 0x22 0xCC RSSI Write Digital Outputs 0xCC 0x23 bit 0 GO0 bit 1 GO1 0xCC bit 0 GO0 bit 1 GO1 Write DAC 0xCC 0x24 Update Period Duty Cycle 0xCC Update Period Duty Cycle Set Max Power 0xCC 0x25 New ...

Page 10: ...to use this command Command 0x41 0x54 0x2B 0x2B 0x2B 0x0D Number of Bytes Returned 4 Response 0xCC 0x43 0x4F 0x4D Exit AT Command Mode The OEM Host should send this command to exit AT Command mode and resume normal operation Command 0xCC 0x41 0x54 0x4F 0x0D Number of Bytes Returned 4 Response 0xCC 0x44 0x41 0x54 Status Request The OEM Host issues this command to request the status of the transceiv...

Page 11: ...alid only for server transceivers Command 0xCC 0x05 Channel Number of Bytes Returned 3 Response 0xCC Channel Parameter Range Channel Sync Channel Sleep Walk Power Down After the host issues this command the client transceiver will issue its In_Range line logic high after entering power down A client in Power Down will remain in sync with a server for a minimum of 2 minutes To maintain synchronizat...

Page 12: ...n the transceiver If Broadcast Packets are selected the transceiver will send its packets to all transceivers on that network Command 0xCC 0x08 Mode Number of Bytes Returned 2 Response 0xCC Mode Parameter Range Mode 0x00 Addressed 0x01 Broadcast Write Destination Address The OEM Host issues this command to the transceiver to change the Destination Address Note Only the three Least Significant Byte...

Page 13: ...led the CL4490 radio may fail to lock onto frequency If it does the radio timeouts after 5 ms and performs a recalibration Command 0xCC 0x12 0x00 0x00 Number of Bytes Returned 3 Response 0xCC Version Status Parameter Range Version Firmware version of radio Status 0x00 Server in range 0x01 Client in range 0x02 Server out of range 0x03 Client out of range Auto Destination Auto Channel The Host issue...

Page 14: ... The equations for converting these 10 bits into analog values are as follows Analog Voltage 10 bits 0x3FF 3 3 V Temperature o C Analog Voltage 0 3 0 01 30 Instantaneous RSSI value dBm 105 0 22 0x3FF 10 bits Command 0xCC 0x21 Port Number of Bytes Returned 3 Response 0xCC Hi ADC Lo ADC Parameter Range Port 0x00 AD In 0x01 Temperature 0x02 Instantaneous RSSI Hi ADC MSB of requested 10 bit ADC value ...

Page 15: ... is not set to 0xE3 Command 0xCC 0x23 Digital Out Number of Bytes Returned 2 Response 0xCC Digital Out Parameter Range Digital Out bit 0 GO0 bit 1 GO1 Write DAC The OEM Host issues this command to write DA_Out to a particular voltage The transceiver uses a PWM Pulse Width Modulator to generate the analog voltage The theory behind a PWM is that a binary pulse is generated with a fixed rate Data 1 a...

Page 16: ... is represented at this pin as an analog voltage 50 duty cycle is half of 3 3V or 1 65V Set Max Power The OEM Host issues this command to limit the maximum transmit power emitted by the transceiver This can be useful to minimize current consumption and satisfy certain regulatory requirements Note The radios are shipped at maximum allowable power Command 0xCC 0x25 Max Power Number of Bytes Returned...

Page 17: ...A 1000 26 398 11 B 1080 26 5 446 68 C 1130 27 501 19 D 1170 27 5 562 34 E 1260 28 630 96 F 1300 28 743 Long Range Mode The OEM Host issues this command to temporarily enable or disable Long Range Mode in the transceiver Note Only available on AC4490LR 1000 transceivers with firmware v6 7 Command 0xCC 0x27 Number of Bytes Returned 2 Response 0xCC Mode Parameter Range Mode 0x00 Disable Long Range Mo...

Page 18: ...valid for both servers and clients Command 0xCC 0x86 Number of Bytes Returned 2 Response 0xCC Channel Parameter Range Channel RF Channel currently being used Read Temperature The OEM Host issues this command to read the onboard temperature sensor The transceiver reports the temperature in o C where 0x00 0x50 corresponds to 0 80 o C and 0xD8 0x00 corresponds to 40 0 o C Command 0xCC 0xA4 Number of ...

Page 19: ...a response to the OEM Host Command N A Number of Bytes Returned 5 Response 0xCC Data MAC3 MAC2 MAC1 Parameter Range Data bit 7 0 Client bit 7 1 Server bits 6 0 RF Channel EEPROM Byte Read Upon receiving this command a transceiver will respond with the desired data from the addresses requested by the OEM Host See EEPROM Parameters Command 0xCC 0xC0 Start Length Number of Bytes Returned 4 Response 0...

Page 20: ...s provide dynamic packet routing and packet accounting ability to the OEM host thereby eliminating the need for extensive programming on the OEM host side API operation utilizes specific packet formats specifying various vital parameters used to control radio settings and packet routing on a packet by packet basis The API features can be used in any combination that suits the OEM s specific needs ...

Page 21: ...powerful command that allows the OEM host to dynamically send data to a single or multiple broadcast transceiver s on a packet by packet basis API Transmit Packet is enabled when bit 1 of the Enhanced API Control byte EEPROM byte 0xC6 is enabled The OEM host must use the following format to transmit a packet over the RF when using Transmit API packets 0x81 Payload Data Length 0x01 0z50 Laird Use T...

Page 22: ...er than those listed below Do not copy one transceiver s EEPROM to another transceiver as doing so may cause the transceiver to malfunction Only the Configuration Utility should be used to copy one configuration into another transceiver Table 5 EEPROM Parameters Parameter EEPROM Address Length Bytes Range Default Description Product ID 0x00 40 Product identifier string Includes revision informatio...

Page 23: ...packets 1 Transmit using Broadcast packets bit 0 Laird Use Only Frequency Offset 0x46 1 0x00 0xFF 0x01 Protocol parameter used in conjunction with Channel Number to satisfy unique regulations CMD Data RX Disable 0x4B 1 0xE3 0xFF 0xFF oxE3 Enable CMD Data RX Disable 0xFF Disable CMD Data RX Disable Transmit Retries 0x4C 1 0x01 0xFF 0x10 Maximum number of times a packet is transmitted when Addressed...

Page 24: ...Timeout specifies the maximum size of an RF packet Note Must be set to a minimum of 6 in order to send the Enter AT command CTS On 0x5C 1 0x01 0xFF 0xD2 CTS will be deasserted High when the transmit buffer contains at least this many characters CTS On Hysterisis 0x5D 1 0x00 0xFE 0xAC Once CTS has been deasserted CTS will be reasserted Low when the transmit buffer is contains this many or less char...

Page 25: ...9C Interface 232 485 TTL 0x9D 0x9E Setup script 01 is stock 0x9F Reserved for future use always 0xFF Protocol Status Receive ACK 0xC0 1 0xE3 oxFF oxFF oxE3 GO0 outputs the Protocol Status and GO1 outputs the Received Acknowledgement signal 0xFF Disable Protocol Status Receive ACK Receive API 0xC1 1 0xE3 0xFF 0xFF 0xE3 Enabled 0xFF Disabled Enhanced API Ctrl 0xC6 1 0xF8 Settings are bit 7 Enhanced ...

Page 26: ...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 ...

Page 27: ... with its clients It must wait until it syncs with server B at which point In_Range is asserted before establishing communications Server B will not be affected and can communicate with its clients See Appendix I API for further details and sample configuration Max Power Max Power provides a means for controlling the RF output power of the AC4490 Output power and current consumption can vary by as...

Page 28: ...network of AC4490 units The System ID is used in conjunction with the Channel Number and serves as an RF password to maintain secure transfers of data The combination of the Channel Number and System ID must be unique to each network of AC4490s to establish communication Multiple servers in the same coverage area must be programmed with different Channel Numbers to prevent inoperability of the net...

Page 29: ...estination address and then exit Command mode to resume normal operation When it is time to communicate with another transceiver the process is repeated However this method costs time and reduction in throughput since unnecessary commands are issued As an alternative the Transmit API command can be used to control packet routing on a packet by packet basis Figure 3 Polling network The simplest imp...

Page 30: ...et all three Destination MAC Address values to 0xFF The remote response is dependent on the OEM s specific needs and equipment In many cases remote radios are connected to dummy terminals without the intelligence to filter out or append specific portions of a packet that is transmitted or received Since the seven bytes of overhead in the Transmit API command are not sent over the RF the remotes re...

Page 31: ...to determine from which radio each packet originated When Enhanced Receive API is enabled every packet received by the transceiver is received in the above format Normal Receive Mode non API If Receive API is not enabled the transceiver receives the reply data only i e ALLGOOD from each transceiver With this receive mode the SAP will not know which radio the data was received from and the messages...

Page 32: ...le Access Network For a more intelligent network a Time Division Multiple Access Network TDMA system can be implemented In this system various radios transmit data to a SAP during an assigned time interval The system is synchronous so that only one radio is transmitting at a time and has full access to the SAP s bandwidth In a TDMA network each radio must store its data for the amount of time betw...

Page 33: ...0 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 This type of implementation requires careful planning and should allow enough time for retries if necessary When full duplex is enabled the radio which initiated the session SAP will transmit during the even numbered hops and the remote radios will transmit only during odd numbered hops ...

Page 34: ...superior interference rejection and multipath immunity The server sends timing beacons on a regular interval and clients hear these beacons and synchronize their hopping to the server Though servers cannot send packets to each other they can hear the timing beacons sent out by other servers Normally the servers ignore these beacons However when Sync to Channel is enabled and a specific server is d...

Page 35: ...e outside of the range of the Hop Master server their Sync Channel should be set to the RF Channel Number of a server with a lower RF Channel Number than its own that is in range of and synchronized to the Hop Master server All collocated servers must be programmed to the same channel set There are 32 available channels for the CL4490 1000 as shown in Table 8 Table 8 RF Channels for AC4490 Channel...

Page 36: ... list correlate to the numbered items in Figure 8 1 The software will open on the Configure tab and you will need to change to the PC Settings tab at the top of the window Note RF Options mentioned in this procedure require that the Show All Options box is selected in the Security Pane on the PC Settings tab of the Configuration Utility To enable the Security Pane see the Enabling the Security Pan...

Page 37: ...airdtech com ramp 37 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 8 PC Settings tab 6 Go to the Configure tab and click the Read Radio button at the bottom right of the screen A message stating Read Successful should appear after a successful read Figure 9 2 2 6 2 6 2 5 2 3 2 4 ...

Page 38: ...ead Successful 7 To configure the Hop Master change the Mode to Server and select Broadcast Mode Make note of the RF Channel Number Once the appropriate changes have been made press the Write Radio button A Write Successful prompt will appear after a successful write Note that the values are shown using hexadecimal representation this can be changed to decimal notation by double clicking on the wo...

Page 39: ...m ramp 39 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 10 Hop Master settings 8 Configure all clients that will communicate with the Hop Master Server as clients in Auto Destination and with the same RF Channel Number as the Hop Master Server Figure 11 and then press the Write Radio button ...

Page 40: ...0610 Figure 11 Client settings 9 Set Server 2 as a server in Broadcast Mode with an RF Channel Number at least 4 5 steps above the RF Channel Number of the Hop Master Under the Radio Features section select the Sync to Channel box and in the Radio RF section set the Sync to Channel to the RF channel of the Hop Master Figure 12 Press the Write Radio button to write the changes to the radios EEPROM ...

Page 41: ...m ramp 41 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 12 Server 2 settings 10 Configure the clients that will communicate with Server 2 as Clients in Auto Destination and with the same RF Channel Number as Server 2 Figure 13 Press the Write Radio to write the changes to the radios EEPROM ...

Page 42: ...erver that is in range of the Hop Master make sure the RF Channel Number of the server is higher than the Sync to Channel 12 Repeat step 11 for all clients that will communicate with each server I ve configured my radios what s next Once you have configured all radios your network should be set up similar to the one shown in Figure 14 The main server or hop master must be powered on anytime that t...

Page 43: ...rd Connectivity Solutions Support Center http ews support lairdtech com www lairdtech com ramp 43 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 14 Sample Centralized Sync to Channel Network configuration ...

Page 44: ...rd Connectivity Solutions Support Center http ews support lairdtech com www lairdtech com ramp 44 Americas 1 800 492 2320 Europe 44 1628 858 940 Hong Kong 852 2923 0610 Figure 15 Sample Daisy Chain Sync to Channel Network configuration ...

Page 45: ...g additional AC4490 technical documents are available from the AC4490 product page Documentation and Datasheet tabs located on the Laird website http www lairdtech com products ac4490 Product Brief AC4490 Hardware Integration Guide Statement of Compliance to EU WEEE Directive and RoHS Directive The following downloads are also available from the RAMP Product Information tab Laird Configuration Uti...

Page 46: ...ake periodic modifications of this product without obligation to notify any person or entity of such revision Copying duplicating selling or otherwise distributing any part of this product or accompanying documentation software without the prior consent of an authorized representative of Laird Technologies Inc is strictly prohibited All brands and product names in this publication are registered t...

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