visa multiple vxi connections

[prh1969]

I have created a VXI instrument simulator to include a port mapper.  I can start my instr simulator and then run another VI that uses an IVI driver to make calls to the simulator with no problems.  But know I need to run multiple copies of my instr simulator on the same PC.  When I try to start the link to the second instr simulator I don't see any new Port Mapper calls and the driver calls into the first instrument simulator.  I use the following resource names for my devices "TCPIP::localhost::inst0::INSTR" and "TCPIP::localhost::instr1::INSTR".  Attached is a copy of the NI Spy log.

Thanks for any help.

[sputnik_rent]

Hi prh1969,

I took a look at your NI Spy captures and saw that it was able to open a session to the second VXI instrument simulator just fine (inst1). What are the port mapper calls that you are looking for? Could you describe what it is the port mapper is supposed to do?

[prh1969]

The port mapper is a VI that listens on port 111 and has the VXI and instr program number and version numbers registered with it.  So that when the client wants to start a link to the instr it first calls the port mapper to find out what port the specified program and version is located at.  Then the client sends all other messages to the specified port.  When I start the first instr it makes three calls to the port mapper to get the VXI core, and two instr port numbers.  All three of these return the same port number because my instr listens on this port and then parses the message based on program number, version number, and procedure number.  This is the expected behavior.  The problem is when I attempt to start another client to a second instrument, there are no calls to the port mapper and messages go to the first instrument.  Boy this is hard to explain!  From looking at the VXI spec an other material it looks like I need a instrument server that would receive the calls from the client and then pass them on to the appropriate device.