Device Not Found error appearing

Output from execution of hp-check -t. What do I need to do to enable em to print to the HP Officejet Pro 8600 Printer?

[cevick@oc7273702785 ~]$ hp-check -t
Saving output in log file: /home/cevick/hp-check.log

HP Linux Imaging and Printing System (ver. 3.14.10)
Dependency/Version Check Utility ver. 15.1

Copyright (c) 2001-13 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Note: hp-check can be run in three modes:
1. Compile-time check mode (-c or --compile): Use this mode before compiling the
HPLIP supplied tarball (.tar.gz or .run) to determine if the proper dependencies
are installed to successfully compile HPLIP.
2. Run-time check mode (-r or --run): Use this mode to determine if a distro
supplied package (.deb, .rpm, etc) or an already built HPLIP supplied tarball
has the proper dependencies installed to successfully run.
3. Both compile- and run-time check mode (-b or --both) (Default): This mode
will check both of the above cases (both compile- and run-time dependencies).

Check types:
a. EXTERNALDEP - External Dependencies
b. GENERALDEP - General Dependencies (required both at compile and run time)
c. COMPILEDEP - Compile time Dependencies
d. [All are run-time checks]
PYEXT SCANCONF QUEUES PERMISSION

Status Types:
    OK
    MISSING - Missing Dependency or Permission or Plug-in
    INCOMPAT - Incompatible dependency-version or Plugin-version

---------------
| SYSTEM INFO |
---------------

 Kernel: 2.6.32-431.30.1.el6.x86_64 #1 SMP Wed Jul 30 14:44:26 EDT 2014 GNU/Linux
 Host: oc7273702785.ibm.com
 Proc: 2.6.32-431.30.1.el6.x86_64 #1 SMP Wed Jul 30 14:44:26 EDT 2014 GNU/Linux
 Distribution: rhel 6.0
 Bitness: 64 bit

-----------------------
| HPLIP CONFIGURATION |
-----------------------

HPLIP-Version: HPLIP 3.14.10
HPLIP-Home: /usr/share/hplip
warning: HPLIP-Installation: Auto installation is not supported for rhel distro 6.0 version

Current contents of '/etc/hp/hplip.conf' file:
# hplip.conf. Generated from hplip.conf.in by configure.

[hplip]
version=3.14.10

[dirs]
home=/usr/share/hplip
run=/var/run
ppd=/usr/share/cups/model/HP
ppdbase=/usr/share/cups/model
doc=/usr/share/doc/hplip-3.14.10
html=/usr/share/doc/hplip-3.14.10
icon=/usr/share/applications
cupsbackend=/usr/lib/cups/backend
cupsfilter=/usr/lib/cups/filter
drv=/usr/share/cups/drv/hp
bin=/usr/bin

# Following values are determined at configure time and cannot be changed.
[configure]
network-build=yes
libusb01-build=yes
pp-build=no
gui-build=yes
scanner-build=yes
fax-build=yes
dbus-build=yes
cups11-build=no
doc-build=yes
shadow-build=no
hpijs-install=no
foomatic-drv-install=no
foomatic-ppd-install=no
foomatic-rip-hplip-install=no
hpcups-install=yes
cups-drv-install=no
cups-ppd-install=yes
internal-tag=3.14.10
restricted-build=no
ui-toolkit=qt4
qt3=no
qt4=yes
policy-kit=no
lite-build=no
udev_sysfs_rules=no
hpcups-only-build=no
hpijs-only-build=no

Current contents of '/var/lib/hp/hplip.state' file:
Plugins are not installed. Could not access file: No such file or directory

Current contents of '~/.hplip/hplip.conf' file:
[last_used]
printer_name =
working_dir = .
device_uri = "hp:/usb/Officejet_Pro_8600?serial=CN31CBWGGH05KC"

[commands]
scan = /usr/bin/xsane -V %SANE_URI%

[upgrade]
notify_upgrade = true
last_upgraded_time = 1422580526
latest_available_version = 3.14.10
pending_upgrade_time = 0

[installation]
version = 3.14.10
date_time = 01/30/2015 12:50:06

[settings]
systray_messages = 0
systray_visible = 0

[fax]
email_address =
voice_phone =

[refresh]
rate = 30
enable = false
type = 1

[polling]
enable = false
device_list =
interval = 5

 <Package-name> <Package-Desc> <Required/Optional> <Min-Version> <Installed-Version> <Status> <Comment>

--------------------------
| External Dependencies |
--------------------------

 policykit Admin-Policy-framework OPTIONAL - 0.96 OK -
 gs Ghostscript REQUIRED 7.05 8.70 OK -
 network Network-wget OPTIONAL - 1.12 OK -
 scanimage Shell-Scanning OPTIONAL 1.0 1.0.21 OK -
 avahi-utils avahi-utils OPTIONAL - 0.6.25 OK -
 dbus DBus REQUIRED - 1.2.24 OK -
 cups CUPS REQUIRED 1.1 1.4.2 OK 'CUPS Scheduler is running'
 xsane SANE-GUI OPTIONAL 0.9 0.997 OK -

-------------------------
| General Dependencies |
-------------------------

 reportlab Python-PDF-Lib OPTIONAL 2.0 2.3 OK -
 libcrypto OpenSSL-Crypto-Lib REQUIRED - 1.0.1 OK -
 pil Python-Image-Lib OPTIONAL - 1.1.6 OK -
 pyqt4-dbus PyQt4-DBUS REQUIRED 4.0 4.6.2 OK -
 libjpeg JPEG-Lib REQUIRED - - OK -
 libpthread POSIX-Threads-Lib REQUIRED - 2.12 OK -
 python-dbus Python-DBUS REQUIRED 0.80.0 0.83.0 OK -
 python-devel Python-SDK REQUIRED 2.2 2.6.6 OK -
 pyqt4 Python-Qt4 REQUIRED 4.0 4.6.2 OK -
 cups-devel CUPS-SDK REQUIRED - 1.4.2 OK -
 sane-devel SANE-SDK REQUIRED - 1.0.21 OK -
 libusb USB-Lib REQUIRED - 1.0 OK -
 sane Scan-Lib REQUIRED - 1.0.21 OK -
 cups-image CUPS-Image-Lib REQUIRED - 1.4.2 OK -
 libnetsnmp-devel SNMP-Networking-SDK REQUIRED 5.0.9 5.5 OK -
 python-xml Python-XML-Lib REQUIRED - 2.0.1 OK -
 python-notify Desktop-notifications OPTIONAL - - OK -

------------------------------
| Compile Time Dependencies |
------------------------------

 gcc gcc-Compiler REQUIRED - 4.4.7 OK -
 libtool Build-tools REQUIRED - 2.2.6 OK -
 make GNU-Build-tools REQUIRED 3.0 3.81 OK -

----------------------
| Python Extentions |
----------------------

 cupsext CUPS-Extension REQUIRED - 3.14.10 OK -
 pcardext PhotoCard-Extension REQUIRED - 3.14.10 OK -
 hpmudext IO-Extension REQUIRED - 3.14.10 OK -

-----------------------
| Scan Configuration |
-----------------------

 hpaio HPLIP-SANE-Backend REQUIRED - 3.14.10 OK 'hpaio found in /etc/sane.d/dll.conf'
 scanext Scan-SANE-Extension REQUIRED - 3.14.10 OK -

------------------------------
| DISCOVERED SCANNER DEVICES |
------------------------------

No Scanner found.

--------------------------
| DISCOVERED USB DEVICES |
--------------------------

No devices found.

---------------------------------
| INSTALLED CUPS PRINTER QUEUES |
---------------------------------

HP-Officejet-Pro-8600
---------------------
Type: Printer
Device URI: hp:/usb/Officejet_Pro_8600?serial=CN31CBWGGH05KC
PPD: /etc/cups/ppd/HP-Officejet-Pro-8600.ppd
PPD Description: HP Officejet Pro 8600, hpcups 3.12.6
Printer status: printer HP-Officejet-Pro-8600 is idle. enabled since Thu 27 Jun 2013 11:52:43 AM EDT
error: Unable to communicate with device (code=12): hp:/usb/Officejet_Pro_8600?serial=CN31CBWGGH05KC
error: Device not found
error: Communication status: Failed

PostScript
----------
Type: Unknown
Device URI: ps:/tmp
PPD: /etc/cups/ppd/PostScript.ppd
PPD Description: Generic PostScript Printer
Printer status: printer PostScript is idle. enabled since Thu 11 Oct 2012 01:24:26 PM EDT
warning: Printer is not HPLIP installed. Printers must use the hp: or hpfax: CUPS backend for HP-Devices.

--------------
| PERMISSION |
--------------

-----------
| SELINUX |
-----------

SELinux disabled Optional - - OK -

-----------
| SUMMARY |
-----------

Missing Required Dependencies
-----------------------------
None

Missing Optional Dependencies
-----------------------------
None

Total Errors: 1
Total Warnings: 1

Done.