I have a DLS 400E ADSL Wireline Simulator and I try to configure it using RS232 interface. It answers for the common commands like *CLS, *IDN? etc. But it returns error (red led and no text answer) for the request about slot status like :SET:SLOT 5? and for the slot configuration commands like :SET:SLOT 5,100 m,INLINE On the other hand it does something and answers for the LOOP configuration commands (which described in the manual for the American versions DLS 400A/H/N/HN). What I'm doing wrong?