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Walkthrough Wednesdays

EX90: Making a Console Cable and Consoling In



This document will provide instruction of how to create an EX90 console cable and console into a unit.

Core Issue

There may be situations where consoling into an EX90 can solve an issue that is not related to hardware.

A console cable for the EX90 is not provided by default or readily available for purchase, but, one can be assembled relatively easy.


Gather the Necessary Tools and Equipment


  1. Soldering iron
  2. Solder
  3. RS232 to TTL/CMOS converter sells the one used here. Cisco does not recommend or endorse Alldav specifically.
  4. DB9 Enclosure Several options are available for the enclosure. This one is being used here.
  5. Cable w/RJ45 connector on one end Any type of cable with an 8P8C (RJ45) connector could used as long
    as pins 1,2,7 & 8 are connected. A standard RJ45 cable is being used here.

You will also need wire strippers (not shown) and coudl need other ancillary tools such as a screwdriver.

Prep the Cable


Strip the sheathing from the wires that correspond to pins 1,2,7& 8.


Connect the RS232 to TTL/CMOS converter

Connect the RS232 to TTL/CMOS converter to the cable and solder the connections.

Wiring Diagram:


Note: The colors used in the wiring diagram don't correspond to the color of the actual wires.

Cable with RS232 to TTL/CMOS converter connected.



Install the Enclosure

Cable with enclosure installed.


The EX90 console cable is now complete.

Make a Console Connection

Locate the Console Port

The EX90 console port is an 8P8C (RJ45) connection and is located on the bottom left corner of the unit.


Connect to the Console Port

Plug the 8P8C (RJ45) end into the console port.


You'll have to lean the unit forward to plug the cable in.
It might be a little awkward to do alone. If someone else is available, ask for their assistance.
As a last resort, lay the unit down. Ensure you have something soft (like a towel) to lay the unit on.

Connect the DB9 to a USB serial adapter and connect to a laptop/PC.

Configure a Terminal Emulator Session

Configure your terminal emulator with the following parameters.

The example uses HyperTerminal forWindows; configuring your terminal emulator may vary slightly.

You should see a login prompt:


This completes making an EX90 console and connecting to the console port.


This also works if you use an old Nokia DLR-3P cable. I found instructions with the pin out here for the Nokia cable -

Cut off the nokia connector and crimp on an RJ45 plug as follows:

BLACK to RJ45 pin 1 (GND)

GREEN to RJ45 pin 2 (RXD)

GRAY to RJ45 pin 7 (TXD)

RED to RJ45 pin 8 (+3.3V)


If you have an iPhone or iPad...

Redpark recently worked with Cisco Telepresence staff to create a cable that connects iPhone and iPad to the console port on EX series and MX series endpoints.

The cable part # is C2-TTL45.

The cable is used with the Get-Console app available on Apple's App Store.