Arduino IDE read TokenGateway data

Hello,

I use Gurux to get token gateway code and it works.

Now I`m trying to use Arduino IDE to get token data,but I got something error.
Here is my Arduino code:

gxTokenGateway objToken;
unsigned char token[20] = {0x31, 0x37, 0x36, 0x32, 0x32, 0x34, 0x34, 0x39, 0x37, 0x30, 0x36, 0x31, 0x31, 0x35, 0x30, 0x34, 0x39, 0x32, 0x35, 0x30};
gxByteBuffer bb;
BYTE_BUFFER_INIT(&bb);
if ((ret = bb_setUInt8(&bb, DLMS_DATA_TYPE_OCTET_STRING)) == 0 &&
(ret = hlp_setObjectCount(sizeof(token), &bb)) == 0 &&
(ret = bb_set(&bb, token, sizeof(token))) == 0)
{
}
dlmsVARIANT params;
var_init(&params);
var_setInt8(&params, 0);
var_addOctetString(&params, &bb);
var_addBytes(&params, token, sizeof(token));
cosem_init(BASE(objToken), DLMS_OBJECT_TYPE_TOKEN_GATEWAY, "0.0.19.40.0.255");
com_method(BASE(objToken), 1, &params);
data = bb_toHexString(&objToken.token);
obj_toString(BASE(objToken), &data);
GXTRACE(PSTR("Ori token : "), data);
obj_clear(BASE(objToken));
free(data);

Response:

:com_method section2 failed. 12
:Ori token : Index: 2 Value:

What`s wrong with my code?
My Arduino IC specification is Mega2560

Bill