Elster communication via Terminal

I guess my first question is, is it possible to use DLMSDirector to connect to an Elster A1700 (or AS230)?

I keep getting 'Failed to receive answer from the modem. Check serial port' - although the modem is dialing the number and the modem attached to the meter is answering (from listening in).

Log (with phone number removed):

GXDLMSDirector 8.2.2108.1901
Log created 08:39:30
08:39:43 Initializing Terminal connection.
System.Exception: Failed to receive answer from the modem. Check serial port.
at GXDLMSDirector.GXDLMSCommunicator.InitTerminal()
at GXDLMSDirector.GXDLMSCommunicator.InitializeConnection(Boolean force)
at GXDLMSDirector.GXDLMSDevice.InitializeConnection()
at GXDLMSDirector.MainForm.Connect(Object sender, GXAsyncWork work, Object[] parameters)
08:41:19 Initializing Terminal connection.
08:41:19 08:41:19.758 Info Opening
08:41:19 08:41:19.758 Info Settings: Port: COM6 Baud Rate: 9600 Data Bits: 8 Parity: None Stop Bits: One Eop: None
08:41:19 08:41:19.764 Sent 41 54 45 30 0D 0A
08:41:19 08:41:19.766 Received 0D 0A 4F 4B 0D 0A
08:41:19 08:41:19.767 Sent 41 54 0D
08:41:19 08:41:19.768 Received 0D 0A 4F 4B 0D 0A
08:41:19 08:41:19.769 Sent 41 54 44 xx xx xx xx xx xx xx xx xx xx xx 0D 0A
08:41:49 08:41:49.783 Info Closing
08:41:49 08:41:49.785 Info Closed
System.Exception: Failed to receive answer from the modem. Check serial port.
at GXDLMSDirector.GXDLMSCommunicator.InitTerminal()
at GXDLMSDirector.GXDLMSCommunicator.InitializeConnection(Boolean force)
at GXDLMSDirector.GXDLMSDevice.InitializeConnection()
at GXDLMSDirector.MainForm.Connect(Object sender, GXAsyncWork work, Object[] parameters)