be sure the following conditions are met for a PCoIP session:

• Network cables are firmly connected and the network jack activity lights are on.
• The Host and zero client are reachable on the network (e.g., subnets are not masked).
• The session type is set to PCoIP in the Session tab of the OSD or Administrative Web Interface.  
• If Connection Management and Host Discovery are disabled in the OCD, be sure the Host Card’s IP and MAC addresses are properly entered in the Session tab of the OSD, or in the zero client's Administrative Web Interface.

If the Host Discovery option is enabled in the OSD: 

• Host Discovery uses the Service Location Protocol (SLP), which requires devices to respond when it discovers them. So, the host PC/workstation should be powered on to have the Host Card to be discoverable.
• Be sure the Host Card and the zero client are on the same subnet. If they are on different subnets, the Host Card may not show up in the list of discovered devices. If so, you may have to disable Host Discovery and enter the Host Card’s IP and MAC address in the OSD to connect a PCoIP session.

• Be sure the host PC is powered on, or the PCoIP session between the zero client and the Host Card is in sleep (indicated by a blinking green Power Button LED on the zero client) after remotely powering down the host PC. If the host PC is remotely powered down and the zero client is restarted (zero client's Power Button LED is not blinking green), you can remotely power up the host PC by establishing a session with the Host Card with the Host Discovery option disabled.