Cisco AIR-AP1242AG-A-K9 Hardware Installation Guide - Page 56

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Cisco Aironet 1240AG Series Access Point Hardware Installation Guide

OL-8371-05

Chapter 3

Troubleshooting 1240AG Series Autonomous Access Points

Low Power Condition

Note

If your access point is connected to in-line power, do not connect the power module to the access point.

Using two power sources on the access point might cause the access point to shut down to protect internal

components and might cause the switch to shut down the port to which the access point is connected. If

your access point shuts down, you must remove all power and reconnect only a single power source.

On power up, the access point is placed into low power mode (both radios are disabled), Cisco IOS

software loads and runs, and power negotiation determines if sufficient power is available. If there is

sufficient power then the radios are turned on; otherwise, the access point remains in low power mode

with the radios disabled to prevent a possible over-current condition. In low power mode, the access

point activates the Status LED low power error indication, displays a low power message on the browser

and serial interfaces, and creates an event log entry (see the

“Checking the Autonomous Access Point

LEDs” section on page 3-2

and

“Inline Power Status Messages” section on page 3-7

).

Intelligent Power Management

The access point requires 12.95 W of power (up to 15.4 W with 100 m CAT 5 Ethernet cable) for full

power operation with both radios, but only needs 6.3 W of power when operating in low power mode

with both radios disabled. To help avoid an over-current condition with low power sources and to

optimize power usage on Cisco switches, Cisco developed Intelligent Power Management, which uses

Cisco Discovery Protocol (CDP) to allow powered devices (such as your access point) to negotiate with

a Cisco switch for sufficient power.

The access point supports Intelligent Power Management and as a result of the power negotiations, the

access point will either enter full power mode or remain in low power mode with the radios disabled.

Note

Independent of the power negotiations, the access point hardware also uses the 802.3af classification

scheme to indicate the power required from the power source. However, the power source cannot report

the power available to the access point unless the power source also supports Intelligent Power

Management.

Some Cisco switches that are capable of supplying sufficient power require a software upgrade to

support Intelligent Power Management. If the software upgrade is not desired, you can configure the

access point to operate in pre-standard compatibility mode and the access point automatically enters full

power mode if these Cisco switches are detected in the received CDP ID field.

When the access point determines that sufficient power is not available for full power operation, an error

message is logged and the Status LED turns amber to indicate low power mode (see the

“Checking the

Autonomous Access Point LEDs” section on page 3-2

and the

“Inline Power Status Messages” section

on page 3-7

).

Tip

If your switch is capable of supplying sufficient power for full operation but the access point remains in

low-power mode, your access point or your switch (or both) might be misconfigured (see

Table 3-2

and

Table 3-3

).

Section	Page
Cisco Aironet 1240AG Series Access Point Hardware Installation Guide	1
Contents	3
Preface	9
Audience	9
Purpose	9
Organization	9
Conventions	10
Related Publications	12
Locating the Product Serial Number	13
Obtaining Documentation, Obtaining Support, and Security Guidelines	14
Overview	15
Product Terminology	15
Autonomous Access Points	15
Lightweight Access Points	16
Guidelines for Using Cisco Aironet Lightweight Access Points	16
Hardware Features	17
Single or Dual-Radio Operation	19
Antennas Supported	19
Ethernet Port	19
Console Port	19
LEDs	19
Power Sources	20
UL 2043 Certification	20
Anti-Theft Features	20
Network Examples with Autonomous Access Points	22
Root Access Point on a Wired LAN	23
Repeater Unit that Extends Wireless Range	24
Central Unit in an All-Wireless Network	25
Bridge Network with Wireless Clients	25
Point-to-Point Bridge Configuration	26
Workgroup Bridge Network	26
Network Example with Lightweight Access Points	27
Installing the Access Point	29
Safety Information	30
FCC Safety Compliance Statement	30
General Safety Guidelines	30
Warnings	30
Unpacking the Access Point	31
Package Contents	31
Basic Installation Guidelines	32
Controller Discovery Process for Lightweight Access Points	32
Deploying the Access Points on the Wireless Network	33
Access Point Layout and Connectors	34
Mounting Overview	35
Mounting on a Horizontal or Vertical Surface	37
Mounting Below a Suspended Ceiling	38
Mounting Above a Suspended Ceiling	39
Mounting Access Point on a Desktop or Shelf	42
Cable Security Bracket	42
Removing the Cable Security Bracket	43
Attaching the Access Point to the Mounting Plate	44
Securing the Access Point	45
Using a Security Cable	45
Securing the Access Point to the Mounting Plate	46
Connecting the Ethernet and Power Cables	48
Connecting to an Ethernet Network with an Inline Power Source	49
Connecting to an Ethernet Network with Local Power	50
Powering Up the Access Point	50
Troubleshooting 1240AG Series Autonomous Access Points	51
Checking the Autonomous Access Point LEDs	52
Checking Basic Settings	53
Default IP Address Behavior	54
Enabling the Radio Interfaces	54
SSID	54
WEP Keys	55
Security Settings	55
Low Power Condition	55
Intelligent Power Management	56
Inline Power Status Messages	57
Configuring Power Using the CLI	59
Issuing the Cisco IOS Command Using the CLI	60
Configuring the Access Point System Power Settings Using a Browser	61
Running the Carrier Busy Test	63
Running the Ping Test	64
Resetting to the Default Configuration	64
Using the MODE Button	65
Using the Web Browser Interface	65
Reloading the Access Point Image	66
Using the MODE Button	66
Web Browser Interface	67
Browser HTTP Interface	67
Browser TFTP Interface	68
Obtaining the Access Point Image File	69
Connecting to the Access Point Locally	70
Obtaining the TFTP Server Software	70
Troubleshooting 1240AG Series Lightweight Access Points	71
Guidelines for Using Cisco Aironet Lightweight Access Points	72
Using DHCP Option 43	72
Checking the Lightweight Access Point LEDs	73
Low Power Condition for Lightweight Access Points	75
Intelligent Power Management	75
Configuring Power Using Controller CLI Commands	76
Manually Configuring Controller Information Using the Access Point CLI	77
Configuring Controller Information	78
Clearing Manually Entered Controller Information	78
Manually Resetting the Access Point to Defaults	78
Returning the Lightweight Access Point to Autonomous Mode	79
Using a Controller to Return the Access Point to Autonomous Mode	79
Using the MODE Button to Return the Access Point to Autonomous Mode	79
MODE Button Setting	80
Obtaining the Autonomous Access Point Image File	80
Connecting to the Access Point Locally	81
Obtaining the TFTP Server Software	82
Translated Safety Warnings	83
Declarations of Conformity and Regulatory Information	85
Manufacturers Federal Communication Commission Declaration of Conformity Statement	86
VCCI Statement for Japan	87
Industry Canada	87
Canadian Compliance Statement	87
European Community, Switzerland, Norway, Iceland, and Liechtenstein	88
Declaration of Conformity with Regard to the 1999/5/EC (R&TTE Directive)	88
Declaration of Conformity for RF Exposure	91
Guidelines for Operating Cisco Aironet Access Points in Japan	92
Japanese Translation	92
English Translation	92
Administrative Rules for Cisco Aironet Access Points in Taiwan	93
Access Points with IEEE 802.11a Radios	93
Chinese Translation	93
English Translation	93
All Access Points	94
Chinese Translation	94
English Translation	94
Operation of Cisco Aironet Access Points in Brazil	95
Access Point Models	95
Regulatory Information	95
Portuguese Translation	95
English Translation	95
Declaration of Conformity Statements	96
Declaration of Conformity Statements for European Union Countries	96
Access Point Specifications	99
Channels and Maximum Power Levels	103
Console Cable Pinouts	105
Overview	106
Console Port Signals and Pinouts	106
Priming Lightweight Access Points Prior to Deployment	107
Configuring DHCP Option 43 for Lightweight Access Points	111
Overview	112
Configuring Option 43 for 1000 Series Access Points	113
Configuring Option 43 for 1100, 1130, 1200, 1240, and 1300 Series Lightweight Access Points	114
Glossary	115

Cisco AIR-AP1242AG-A-K9 Hardware Installation Guide - Page 56

Intelligent Power Management, Inline Power Status Messages

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