Receive fax

Hi:
I want to receive fax with an E1 link connected to A102d card from a fax machine,but after dialling the phone number, it connect then will be busy.in fact asterisk can’t detect fax.These are zapata.conf, extensions.conf file and debug in console:

extensions.conf:
[from-pstn]
exten => 9711315,1,Answer()
exten => fax,1,SetVar(FAXFILE=/tmp/test.tif)
exten => fax,2,rxfax(FAXFILE)
9711315 is E1 number.

zapata.conf
[channels]
context=default
usecallerid=yes
hidecallerid=no
callwaiting=yes
usecallingpres=yes
callwaitingcallerid=yes
threewaycalling=yes
transfer=yes
canpark=yes
cancallforward=yes
callreturn=yes
echocancel=yes
echocancelwhenbridged=yes
faxdetect=from-pstn
relaxdtmf=yes
rxgain=0.0
txgain=0.0
group=1
callgroup=1
pickupgroup=1
immediate=no

;Sangoma A102 port 1 [slot:6 bus:1 span:1]
switchtype=national
context=from-pstn
group=0
signalling=pri_cpe
channel =>1-15,17-31

– Executing [9711315@from-pstn:1] Answer(“Zap/6-1”, “”) in new stack
– Accepting call from ‘3318545’ to ‘9711315’ on channel 0/6, span 1
== Auto fallthrough, channel ‘Zap/6-1’ status is ‘UNKNOWN’
– Hungup ‘Zap/6-1’

I’ve installed spandsp and app_rxfax.
I’d appreciate any help and idea.