opensmppbox and nowsms - not recognise message as unicode

my config is as below:
nowsms -> opensmppbox -> kannel -> http smsc -> php scriptwhen we sent unicode, the kannel message log showed as  ascii. NowSMS already 
set data_coding=8 (DCS).
the unicode message: 你好 (hex code = 4F60597D)
=================
opensmppbox config
route-to-smsc = testapi
=================opensmppbox log
2015-09-16 18:24:47 [16053] [2] DEBUG:  sms.udhdata:2015-09-16 18:24:47 [16053] 
[2] DEBUG:  sms.msgdata:2015-09-16 18:24:47 [16053] [2] DEBUG:  Octet string at 
0x18d49d0:2015-09-16 18:24:47 [16053] [2] DEBUG:    len:  42015-09-16 18:24:47 
[16053] [2] DEBUG:    size: 52015-09-16 18:24:47 [16053] [2] DEBUG:    
immutable: 02015-09-16 18:24:47 [16053] [2] DEBUG:    data: 4f 60 59 7d         
                              O`Y}2015-09-16 18:24:47 [16053] [2] DEBUG:  Octet 
string dump ends.
================
kannel debug log
GET /sms/smpp-test.php?from=&to=8691239123&text=O%60Y%7D HTTP/1.1..Host: 
xxx.xxxxxxxxx.com..Connection: keep-alive....
kannel.conf
group = smscsmsc = httpsmsc-id = testapisystem-type = generic#port = 80send-url 
= "http://xxx.xxxxxxxxx.com/sms/smpp-test.php?from=%P&to=%p&text=%b";

==============
I just pass the message as ascii to me. if opensmppbox does not do the 
conversion, i could do it but i could not know if the message is unicode or not 
when returned by HTTP SMSCpls advise.