ibwrt gets this error eadr

[w_o_l_f_e]

hello
i am running win2000 with excel2000 visual basic.
i included the niglobal and vbib32.
buffer ="R1"
call sendifc(gpib) 'so gpib is 0
call enablelocal... 'i just want only single devise
call enableremote..
call ibwrt(gpib,buffer$)
the nispy interpretes that so
ibwrt(0,"R1",2(0x2)) 0x8130 EADR 0x0000
if i write that R1 with the communicator the result is
ibwrt(UDO,"R1",2(0x2)) 0x0100 0 0x0002
my question is what is UDO?
then i tried the SEND(0,0x0007,"R1",2(0x2),Nullend(0x00))
there were no errors but the multimeter didnt change the settings
does anyone hav a solution for me

[TN]

EADR Error Code:
Make sure that the GPIB interface is addressed correctly before calling ibrd, ibwrt, RcvRespMsg, or SendDataBytes.

Avoid calling ibgts except immediately after an ibcmd call. (ibcmd causes ATN to be asserted.)