Tvheadend

hi
I am trying to see tvheadend channels from another pc.
if I use in vlc in network stream this address http://pc-ip:9981/playlist/channels
vlc show and play the channels.

I want to use tvheadend to show and play those channels in another computer.
I tries add that address in muxes (under iptv) but it failed to scan.

2014-05-16 16:31:17.000 mpegts: 192.168.14.171:9981/playlist/channels - tuning on IPTV
2014-05-16 16:31:17.000 iptv: 192.168.14.171:9981/playlist/channels - invalid URL [192.168.14.171:9981/playlist/channels]
2014-05-16 16:31:17.000 mpegts: 192.168.14.171:9981/playlist/channels - failed to start, try another

2014-05-16 16:34:07.000 mpegts: http://192.168.14.171:9981/playlist/channels - tuning on IPTV
2014-05-16 16:34:07.000 subscription: 'initscan' subscribing to mux, weight: 2, adapter: 'IPTV', network: 'iptv', mux: 'http://192.168.14.171:9981/playlist/channels'
2014-05-16 16:34:12.000 mpegts: http://192.168.14.171:9981/playlist/channels - initial scan no data, failed
2014-05-16 16:34:12.000 subscription: "initscan" unsubscribing

thanks for your help.