Laird AC4490 User manual

AC4490
User Guide
Version 4.5
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AC4490 User Guide
Version 4.5
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REVISION HISTORY
Version
Date
Changes
Approved By
1.0
Initial Release
Chris Downey
1.1
10/2012
Major changes and revisions throughout document
Chris Downey
2.0
04/5/2013
Major changes and revisions; updated format and
data
Chris Downey
3.0
--
--
Chris Downey
4.0
--
--
Chris Downey
4.1
10 Dec 2013
Updated download instructions for Laird
Configuration Utility in section How do I configure
Sync to Channel?
Chris Downey
4.2
11 Dec 2013
Separated into two separate docs (Hardware
Integration Guide and User Guide).
Added a Related Documents section.
Sue White
4.3
6 Feb 2013
Fixed return data for EEPROM Byte Write.
Chris Downey
4.4
15 Apr 2015
Updated contact information 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 Exposure/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 preceding statement must be included as a CAUTION statement in manuals for OEM
products to alert users on FCC RF Exposure compliance.
Caution: Any change or modification not expressly approved by Laird could void the user’s authority to
operate the equipment.

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CONTENTS
AC4490 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 Documents and Files .................................................................................................................... 45

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AC4490 RF TRANSCEIVER
The compact AC4490 900 MHz transceiver can replace miles of cable in harsh industrial environments. Using
field-proven frequency hopping spread spectrum (FHSS) technology which needs no additional FCC licensing
in the Americas, OEMs can easily make existing systems wireless with little or no RF expertise.
Overview
The AC4490 is a cost effective, high performance, frequency hopping spread spectrum transceiver designed
for integration into OEM systems operating under FCC part 15.247 regulations for the 900 MHz ISM band.
AC4490 transceivers provide an asynchronous TTL level serial interface for OEM Host communications, which
include both system and configuration data. The Host supplies system data for transmission to other Host(s).
Configuration data is stored in the on-board EEPROM. All frequency hopping, synchronization, and RF system
data transmission/reception is performed by the transceiver.
To boost data integrity and security, the AC4490 uses Laird’s field-proven FHSS technology featuring optional
Data-Encryption Standards (DES). Fully transparent, these transceivers operate seamlessly in serial cable
replacement applications.
AC4490 transceivers can operate in Point-to-Point, Point-to-Multipoint, Client-Server, or Peer-to-Peer
architecture. One transceiver is configured as a server with one or many client-configured transceivers
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, specifications, interface definition,
configuration information and mechanical drawings. The OEM is responsible for ensuring the final product
meets all appropriate regulatory agency requirements listed herein before selling any product.
Additionally, this document contains a list of Related Documents and Files.
Note: Unless mentioned by name, the AC4490 module is referred to as the “radio” or “transceiver”.
Individual naming is used to differentiate product specific features. The host (PC / Microcontroller /
Any device to which the AC4490 module is connected) will be referred to as “OEM Host”.
FEATURES
Networking and Security
Generic I/O digital lines and integrated DAC/ADC
functions
Retries and Acknowledgements
API Commands to control packet routing and
acknowledgement on a packet-by-packet basis
Frequency Hopping Spread Spectrum for security
and interference rejection
Customizable RF Channel number and system ID
Dynamic link analysis, remote radio discovery
Low latency and high throughput
Hardware Protocol Status monitoring
Easy to Use
Continuous 76.8 Kbps RF data stream
Software selectable interface baud rates
from 1200 bps to 115.2 Kbps
Low cost, low power and small size ideal for
high volume, portable and battery powered
applications
All modules are qualified for Industrial
temperatures (-40° C to 85° C)
Advanced configuration available using AT
commands

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THEORY OF OPERATION
RF Architecture
The AC4490 utilizes a server-client network architecture where all clients synchronize their hopping to the
server. The server transmits a beacon during the first 20 milliseconds of every hop. The client transceivers
listen for this beacon and, upon hearing it, assert their In_Range Low and synchronize hops with the server.
Each network consists of only one server. There should never be two servers on the same RF channel number
in the same coverage area because the interference between the two servers will severely hinder RF
communications. For those applications requiring collocated servers, Laird recommends using the Sync-to-
Channel feature, further explained in Appendix I: Sync-to-Channel.
Modes of Operation
The AC4490 has three different operating modes:
Transmit mode
Receive mode
Command mode
If the transceiver is not communicating with another radio, it is in Receive mode actively listening for a
beacon from the server. If the client determines that the beacon is from a server operating on the same RF
channel and system ID, it responds by asserting In_Range Low. A transceiver enters Transmit or Command
mode when the OEM host sends data over the serial interface. The state of the CMD Data pin (Pin 17) or
the data contents determine which of the two 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 RF packet is sent only to the receiver specified in the
destination address. To increase the odds of successful delivery, the packet uses transmit
retries. Transparent to the OEM host, the sending radio sends the RF packet to the intended
receiver. If the receiver receives the packet error-free it returns an RF Acknowledgement in
the same 20 ms hop. If a Receive Acknowledgement is not received, the radio uses a
transmit retry to resend the packet. This continues until either an acknowledgement is
received or all transmit retries are used. The received packet is only sent to the OEM Host if
and when it is received free of errors.
Broadcast
Packets
When sending a broadcast packet, the RF packet is sent to every eligible transceiver on the
network. To increase the odds of successful delivery, it uses broadcast attempts. Transparent
to the OEM host, the sending radio sends the RF packet to the intended receiver(s).
Unlike Transmit Retries, all broadcast attempts are used, regardless of when the RF packet is
actually received. RF acknowledgments are not sent or received when a broadcast packet is
transmitted. If the packet is received on the first attempt, the receiver ignores the remaining
broadcast attempts. The received packet is only sent to the OEM host if and when it is
received free of errors.

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Receive Mode
When a transceiver is not in Transmit or Command mode, it is in Receive mode listening 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.
Command data can be either EEPROM configuration or on-the-fly commands.
Figure 1: Pending RF Buffer Flow

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Figure 2: Pending Data in Buffer Flow

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AC4490 CONFIGURATION
AT Commands
The AT Command mode implemented in the AC4490 creates a virtual version of the Command/Data pin. The
“Enter AT Command Mode” Command asserts this virtual pin Low (to signify Command Mode) and the “Exit
AT Command Mode” Command asserts this virtual pin High (to signify Data). Once this pin has been asserted
Low, all On-the-Fly CC Commands documented in the manual are supported.
Note: The Command/Data RX Disable feature can be enabled in firmware versions 8.6+. When enabled in
EEPROM, the radio disables the RF receiver while pin 17 (Command/Data) is Low. To ensure that
the radio is not in the middle of transmitting data to the OEM Host, the host should be prepared
to receive data for up to 20ms after taking pin 17 Low.
On-the-Fly Control
Commands
The AC4490 transceiver contains static memory that holds many of the parameters
that control the transceiver operation. Using the “CC” command set allows many of
these parameters to be changed during system operation. Because the memory
these commands affect is static, when the transceiver is reset, these parameters will
revert back to the settings stored in the EEPROM. While in CC Command mode
using pin 17 (Command/Data), the RF interface of the transceiver is still active.
Therefore, it can receive packets from remote transceivers while in CC Command
mode 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 transceiver or the transceiver will not
recognize the command.
The link between the OEM host and the transceiver does not need to resync when
exiting Command Mode. Acknowledgements will be sent while in Command Mode,
but the packet will be dumped on the receiving end. However, if an RF packet is
received before the Interface Timeout expires on a CC Command, the transceiver will
send the packet to the OEM Host before sending the CC Command response.
When an invalid command is sent, the radio scans the command to see if it has a
valid command followed by bytes not associated with the command, in which case
the radio discards the invalid bytes and accepts the command. In all other cases, the
radio returns the first byte of the invalid command to the user and discards the rest.
Table 1: Command Quick Reference
Command Name
Command (All Bytes in Hex)
Return (All Bytes in Hex)
Enter Command Mode
0x41
0x54
0x2B
0x2B
0x2B
0x0D
0xCC
0x43
0x4F
0x4D
Exit Command Mode
0xCC
0x41
0x54
0x4F
0x0D
-
0xCC
0x44
0x41
0x54
Status Request
0xCC
0x00
0x00
-
-
-
0xCC
Firmware
Version
0x00: Server
0x01: Client in range
0x03: Out of range
Change Channel
0xCC
0x02
New Channel
-
-
0xCC
New Channel
-
Change Server/Client
0xCC
0x03
0x00: Server
0x03: Client
-
-
0xCC
Firm-ware
Version
0x00: Server
0x03: Client
Change Sync
Channel
0xCC
0x05
New Sync
Channel
-
-
0xCC
New Sync
Channel
-
-

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Command Name
Command (All Bytes in Hex)
Return (All Bytes in Hex)
Sleep Walk Power
Down
0xCC
0x06
-
-
-
-
0xCC
Channel
-
-
Sleep Walk Wake Up
0xCC
0x07
-
-
-
-
0xCC
Channel
-
-
Broadcast
Packets
0xCC
0x08
0x00: Addressed
0x01: Broadcast
-
0xCC
0x00 or
0x01
-
-
Write Destination
Address
0xCC
0x10
Byte 4 of
Dest. MAC
Byte 5
Byte 6
0xCC
Byte 4 of
Dest.MAC
Byte 5
Byte 6
Read Destination
Address
0xCC
0x11
-
-
-
-
0xCC
Byte 4 of
Dest. MAC
Byte 5
Byte 6
Forced Calibration
0xCC
0x12
0x00
0x00
-
-
0xCC
Firm-ware
Version
0x00: Server in
Normal Operation
0x01: Client in
Normal Operation
0x02: Server in
Acquisition Sync
0x03: Client in
Acquisition Sync
Auto Destination
0xCC
0x15
bit-0: Auto Destination
bit-1: Auto Channel
bit-4: Enable Auto Destination
bit-5: Enable Auto Channel
0xCC
bit-0: Auto Destination
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 Max Power
-
0xCC
Max Power
-
-
Report Last Packet
RSSI
0xCC
0x26
-
-
-
-
0xCC
RSSI
-
-
Long Range Mode1
0xCC
0x27
0x00: Normal Mode (Disabled)
0x01: Long Range Mode (Enabled)
0xCC
0x00: Normal Mode (Disabled)
0x01: Long Range Mode (Enabled)
Transmit Buffer Empty
0xCC
0x30
-
-
-
-
0xCC
0x00
-
-
Disable Sync to
Channel
0xCC
0x85
-
-
-
-
0xCC
Channel
-
-
Deep Sleep Mode
0xCC
0x86
-
-
-
-
0xCC
Channel
-
-
Enter Probe
0xCC
0x8E
0x00: Enter Probe
0x01: Exit Probe
-
0xCC
0x00 or
0x01
-
-
Read Temperature
0xCC
0xA4
-
-
-
-
0xCC
Temp (C)
-
-
Read Temperature at
last calibration
0xCC
0xA5
-
-
-
-
0xCC
Temp (C)
EEPROM Byte Read
0xCC
0xC0
Start Address
Length
0xCC
Start
Address
Length
Data
EEPROM Byte Write
0xCC
0xC1
Start Address
Length
Data
Starting Address
Length
Data
written
Soft Reset
0xCC
0xFF
-
-
-
-
-
-
-
-
1. Available only on AC4490LR-1000 transceivers.

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Command Descriptions
Enter AT Command Mode
Prior to sending this command, the OEM Host must ensure that the transceiver’s RF transmit buffer is empty.
If the buffer is not empty, the radio will interpret the command as data and it will be sent over the RF. This
can be accomplished by waiting up to one second between the last packet and the AT command.
Note: RF Packet Size must be set to a minimum of 6 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 transceiver.
Command: <0xCC> <0x00> <0x00>
Number of Bytes Returned: 3
Response: <0xCC> <Version> <Status>
Parameter Range:
<Version> = Firmware version of radio
<Status> = 0x00: Server
0x01: Client in Range
0x03: Client out of Range
Change Channel
The OEM Host issues this command to change the channel of the transceiver.
Command: 0xCC 0x02 <Channel>
Number of Bytes Returned: 2
Response: 0xCC <Channel>
Parameter Range: <Channel> = RF Channel in use

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Change Server/Client
The OEM Host issues this command to change the mode of the transceiver from server to client and vice
versa.
Command: <0xCC> <0x03> <Mode>
Number of Bytes Returned: 3
Response: <0xCC> <Version> <Mode>
Parameter Range:
<Mode> = 0x00: Server
0x03: Client
<Version> = Firmware version of radio
Change Sync Channel
The OEM Host issues this command to change the sync channel byte and enable sync to channel. See
Appendix I: Sync-to-Channel for more information.
Note: Valid 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 synchronization with the server, the client should re-sync at least once every 2 minutes. This is done
by sending the Power Down Wake Up command and waiting for the In_Range line to issue logic low. Once
this occurs, the client is in sync with the server and can be put back into power-down mode.
Note: This command is valid only for client transceivers.
Command: <0xCC> <0x06>
Number of Bytes Returned: 2
Response: <0xCC> <Channel>
Parameter Range: <Channel> = RF Channel currently being used

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Sleep Walk Power-Down Wake Up
The OEM Host issues this command to bring the client transceiver out of Power Down mode.
Note: This command is valid only for client transceivers.
Command: <0xCC> <0x07>
Number of Bytes Returned: 2
Response: <0xCC> <Channel>
Parameter Range: <Channel> = RF Channel currently being used
Broadcast Packets
The OEM Host issues this command to change the transceiver operation between Addressed Packets and
Broadcast Packets. If Addressed Packets are selected, the transceiver will send all packets to the transceiver
designated by the Destination Address programmed in 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 Bytes of the MAC Address are used for packet delivery.
Command: <0xCC> <0x10> <MAC3> <MAC2> <MAC1>
Number of Bytes Returned: 4
Response: <0xCC> <MAC3> <MAC2> <MAC1>
Parameter Range: <MAC> = 0x00 - 0xFF corresponding to 3 LSB’s of destination MAC Address
Read Destination Address
The OEM Host issues this command to the transceiver to read the destination address.
Note: Only the three Least Significant Bytes of the MAC Address are used for packet delivery.
Command: <0xCC> <0x11>
Number of Bytes Returned: 4
Response: <0xCC> <MAC3> <MAC2> <MAC1>
Parameter Range: <MAC> = 0x00 - 0xFF corresponding to 3 LSB’s of destination MAC Address

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Auto Calibration (Forced Recalibration)
When enabled, Auto Calibrate causes the radio to measure the temperature every 30 to 60 seconds. If the
temperature changes more than 30ºC from the last calibration, the radio will initiate a recalibration.
During the recalibration, the radio will not assert CTS high. Recalibration can take up to 3 seconds and the
command response will not be sent to the OEM Host until recalibration is complete.
Note: If Auto Calibration is disabled , 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 issues this command to change the Auto Destination & Auto Channel settings. When issuing this
command, the Auto Destination/Auto Channel settings is only changed if the corresponding enable bit is set.
Command: <0xCC> <0x15> <Auto Dest>
Number of Bytes Returned: 2
Response: <0xCC> <Auto Dest>
Parameter Range:
<Auto Dest>= bit 7: Ignored
bit 6: Ignored
bit 5: Enable Auto Chan. Modification
bit 4: Enable Auto Dest. Modification
bit 3: Ignored
bit 2: Ignored
bit 1: Auto Channel
bit 0: Auto Destination

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Read Digital Inputs
The OEM Host issues this command to read the state of both digital input lines.
Command: <0xCC> <0x20>
Number of Bytes Returned: 2
Response: <0xCC> <Digital In>
Parameter Range:
<Digital In> = bit-0: GI0
bit-1: GI1
Read ADC
The OEM Host issues this command to read any of the three onboard 10-bit A/D converters. Because the RF is
still active in On-the-Fly Command Mode, the transceiver will not process the command until there is no
activity on the network. The Read RSSI command is therefore useful for detecting interfering sources but will
not report the RSSI from a remote transceiver on the network. 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
<Lo ADC> = LSB of requested 10-bit ADC value
Report Last Valid RSSI
Since RSSI values are only valid when the local transceiver is receiving an RF packet from a remote transceiver,
instantaneous RSSI can be tricky to use. Therefore, the transceiver stores the most recent valid RSSI value as
measured the last time the transceiver received a packet or beacon. The Host issues this command to retrieve
that value.
Note: This value will default to 0xFF on a client and 0x00 on a server if no valid RSSI measurement has
been made since power-up.
Command: <0xCC> <0x22>
Number of Bytes Returned: 2
Response: <0xCC> <Last Valid RSSI>

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Table 2: Received Signal Strength
RSSI (dBm)
Hex Value
RSSI (dBm)
Hex Value
-92
C0
-72
63
-91
BC
-71
5F
-90
BB
-70
5B
-89
B9
-69
58
-88
B8
-68
54
-87
AE
-67
4F
-86
A9
-66
4B
-85
A2
-65
47
-84
92
-64
43
-83
8D
-63
3D
-82
86
-62
2A
-81
82
-60
25
-80
7D
-58
1A
-79
79
-56
16
-78
75
-54
13
-77
72
-52
11
-76
6F
-50
0E
-75
6B
-48
0D
-74
68
-46
0C
-73
66
-44
0B
Note: The receiver is saturated after -45 dBm and cannot accurately measure the RSSI above -45 dBm.
Write Digital Outputs
The OEM Host issues this command to write both digital output lines to particular states.
Note: This command should only be used when Protocol Status (0xC2) 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>) and duty cycle (<Data 2>). As such, this pin toggles between High &
Low. This signal is filtered via an on-board R-C circuit and an analog voltage is generated.
Duty cycle specifies the ratio of time in one cycle that the pulse spends High proportionate to the amount of
time it spends Low. So, with a duty cycle of 50% (0x80), the pulse is High 50% of the time and Low 50% of
the time; therefore the analog voltage would be half of 3.3V or 1.65V. A broad filter has been implemented
on the transceiver and there is no advantage to using a slower update period. Generally, a faster update
period is preferred.

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Command: <0xCC> <0x24> <Data1> <Data2>
Number of Bytes Returned: 3
Response: <0xCC> <Data1> <Data2>
Parameter Range: <Data1> = Period of PWM, Hex value
<Data2> = Duty Cycle of PWM, Hex value
Data1 = (Tperiod * 14.74566)- 1 ; Where Tperiod == Period of the PWM in seconds
255 Data1 value is then converted from decimal to hex
Data2 = DCpercentage * 255 ; Where DCpercentage == duty cycle of the PWM in decimal percent (50% = 0.5)
Note: The duty cycle 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: 2
Response: <0xCC> <Max Power>
Parameter Range: <Max Power>= New Max Power setting
Output Power
Table 3: AC4490-200
EEPROM Value
(Hex)
Current (mA)
dBm
mW
0
61
-22
0.01
1
64
-9
0.13
2
65
-3
0.5
3
66
1
1.26
4
67.5
4
2.51
5
70
7
5.01
6
73
9
7.94
7
77
10.5
11.22
8
83
12
15.85
9
88
13.5
22.39
A
93.5
14.5
28.18
B
99
15.5
35.48
C
105
16.5
44.67
D
110.5
17
50.12
E
114.5
17.5
56.23
F
117.5
18.5
70.79
1E
126
19.5
89.13

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EEPROM Value
(Hex)
Current (mA)
dBm
mW
60
127.5
20
100
Table 4: AC4490-1000
EEPROM Value
(Hex)
Current
(mA)
dBm
mW
0
430
-1
0.79
1
430
9
7.94
2
470
14
25.12
3
520
16.5
44.67
4
560
19
79.43
5
650
20.5
112.2
6
740
22
158.49
7
780
23
199.53
8
870
24.5
281.84
9
950
25
316.23
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 Mode
0x01: Enable Long Range Mode
Transmit Buffer Empty
The OEM Host issues this command to determine when the RF transmit buffer is empty. The Host will not
receive the transceiver response until that time.
Command: <0xCC> <0x30>
Number of Bytes Returned: 2
Response: <0xCC> <0x00>

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Disable Sync-to-Channel
The OEM Host issues this command to disable Sync-to-Channel mode. See Appendix I: API for more
information.
Note: This command is valid only for servers.
Command: <0xCC> <0x85>
Number of Bytes Returned: 2
Response: <0xCC> <Channel>
Parameter Range: <Channel> = RF Channel currently being used
Deep Sleep Mode
The OEM Host issues this command to put the transceiver into Deep Sleep mode. Once in Deep Sleep mode,
the transceiver disables all RF communications and will not respond to any further commands until being
reset or power-cycled.
Note: This command is 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 Bytes Returned: 2
Response: <0xCC> <Temp>
Parameter Range: <Temp> = Temperature of module
Read Temperature at Last Calibration
The OEM Host issues this command to read the temperature of the radio at the time of its last calibration.
The transceiver reports the temperature in o C where 0x00 - 0x80 corresponds to 0 - 80o C and where 0xD8 -
0x00 is the two’s complement representation corresponding to -40 - 0 o C.
Note: 0xD8 is a twos complement representation of -40 –0.
Command: <0xCC> <0xA5>
Number of Bytes Returned: 2
Response: <0xCC> <Temp>
Parameter Range: <Temp> = Temperature at last calibration

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Probe
When the OEM Host issues this command, the transceiver sends out a query every 500 ms. The transceivers
randomly choose a query to respond to. After responding to a probe, the transceiver will wait at least 10
seconds before responding to another probe.
Note: This command can only be sent from a server radio.
Command: <0xCC> <0x8E> <Probe>
Number of Bytes Returned: 2
Response: <0xCC> <Probe>
Parameter Range:
<Probe> = 0x00: Disable Probe Mode
0x01: Enable Probe Mode
Transceiver’s Response
Upon hearing the remote transceiver’s probe acknowledge, the transceiver sends 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: <0xCC> <Start> <Length> <Data>
Parameter Range:
<Start> = Address to begin reading from
<Length> = Length of bytes to read
<Data> = Requested data
EEPROM Byte Write
Upon receiving this command, a transceiver will write the data byte to the specified address but will not echo
it back to the OEM Host until the EEPROM write cycle is complete (up to 10 ms).
Multiple byte writes of up to 128 bytes are allowed. An EEPROM boundary exists between addresses 0x7F
and 0x80. No single EEPROM write command shall write to addresses on both sides of that EEPROM
boundary. See EEPROM Parameters.

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Note: Only the last byte written will be displayed in the command response.
Command: <0xCC> <0xC1> <Start> <Length> <Data>
Number of Bytes Returned: 4+
Response: <Starting Address> <Length> <Data written>
Parameter Range:
<Start> = Address to begin writing from
<Length> = Length of bytes to write
<Data> = Last byte of data written
Reset
The OEM Host issues this command to perform a soft reset of the transceiver. Any transceiver settings
modified by CC commands will revert to the default values stored in the EEPROM.
Command: <0xCC> <0xFF>
Number of Bytes Returned: None
Response: None
API Control
API Control is a powerful feature offered by the AC4490. When enabled, the API Receive Packet, API
Transmit Packet, API Send Data Complete and Enhanced API Receive Packet features 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.
Receive API Packet
Note: Implemented in firmware v.6.3 and later.
By default, the source MAC is not included in the received data string sent to the OEM host. For applications
where multiple radios are sending data, it may be necessary to determine the origin of a specific data packet.
Receive API Packet can be enabled to determine the sender of a message. This causes the receiving radio to
add a header to the received packet detailing the length of the data packet and the sender’s MAC address.
The format of the Receive API Packet is:
0x83
Payload Data Length
Sender’s MAC
Payload Data
Note: If Receive API is enabled, the Enhanced API Receive feature should be disabled by clearing bit-0 of
the Enhanced API control byte, EEPROM address 0xC6.