GPIB timeout when writing to ILX 3742b

Hello,

I am trying to drive my ILX 3742b Lightwave by means of GPIB 488.2 with MATLAB 2016b.

Here is the problem:

When I launch tmtool, I can detect the instrument and create the object.

Data format is '%s\n' and EOI & EOS mode are setted like this:

EOImode: on

EOSCharCode: LF

EOSmode: none

If I launch the query "*IDN?", I get the right answer from the instrument. It also works fine if I pass it as a writing and then I separatly read the answer.

If I try to write a command to the instrument, for example 'LAS:OUT ON', it is properly sent to the instrument. However, if I try to do any action again (write, query and read) I receive a time out. After this, I can again communicate with the instrument.

I found out that if I send a query made up of a command followed by a question (for example 'LASOUT ON; *IDN?', please note the ';' which separates the two commands) I can immedately communicate again with the instrument, after the execution of the first command and the right answer to the question.

However, if I send 'LAS:OUT ON' as a single query, I get the time out just after the command is correctly executed: the instrument output turn on, but since nothing is sent from the instrument to the computer, I get the timeout.

I also get the timeout, if I try to read after sending 'LAS:OUT ON' as a write command.

The result of the query 'TERM?', which asks the instrument for the terminator characters, is '0', which from the instrument manual stands for < CR ><NL><^END>. However, I have the same behaviour if I set the format to "%s\r\n".

As a final remark, I would like to stress the fact that by using NI MAX for testing the device, I get a similar behaviour if I use the "Communicate with instrument" tool, while I can correctly communicate with the instrument if I use "Open VISA test panel" tool.

I can also correctly communicate with the instrument if I use LabView 2014.

Thank you in advance for any answer,

Marcello