My files from Oscam-emu are as follows:
oscam.conf
[global]
disablelog = 0
disableuserfile = 0
usrfileflag = 0
maxlogsize = 10
preferlocalcards = 1
saveinithistory = 1
lb_mode = 0
unlock_parental = 1
[cs378x]
port = 12005
[webif]
httpport = 8081
httpallowed = 10.0.0.0-10.255.255.255,172.16.0.0-172.31.255.255,192.168.0.0-192.168.255.255,127.0.0.1
[dvbapi]
enabled = 1
pmt_mode = 6
au = 0
user = dvbapiau
boxtype = dreambox
oscam.server
[reader]
label = "main_cardsharing.cc_XXXXX"
protocol = newcamd
key = 0102030405060708091011121314
device = servXX.com,XXXXX
user = login
password = password
group = 1
audisabled = 1
inactivitytimeout = 300
ident = 0500:060С00,042300,041700,023100,042800,042820,043800,050C00,041200,050F00,024700
[reader]
label = "main_cardsharing.cc_XXXXX"
protocol = newcamd
key = 0102030405060708091011121314
device = servXX.com,XXXXX
user = login
password = password
group = 1
audisabled = 1
inactivitytimeout = 300
ident = 1861:000000,007001,007101
oscam.user
[account]
user = dvbapiau
pwd =
disabled = 0
group = 1
au = 1
[account]
user = 2nd_box
pwd = 2nd_box
group = 1
Please be noted that this is not universal config valid for all receivers and it does not mean that it will work for you. My version of oscam is OSCam downloaded from the feed (Bluepanel in Dreamboxes): 1.20-unstable_svn.
I have VU+Zero and it works with my receiver.
If you fail with these settings, my advice is to find any DM920HD support forum and to look for any oscam related information there. Your receiver is relatively new and, probably, has poor support. Try to find any information on the images (firmware) used in your receiver and read forums re: emulator behavior under your particular image.