MSD Chemstation won't open - message "in use by another session"

I ran into this same issue when trying to set up our GCMS computer for network access. For our system the modules were communication on predefined IP addresses (which I found out latter) The pc needed to be at IP 10.1.1.1 under subnet mask 255.255.255.0 in order for chemstation to pass its communication check on opening, otherwise the check would fail and the software would close. I believe by default the system (agilent 7980A GC) is set up this way. When you start chemstation it will ping each IP for the separate modules you have. Take note of what is says the IP addresses for the different modules are. You can check what the actual IP address for each module isFor us (on LAN connection with modules) the IP address for modules are as follows:

PC 10.1.1.1

GC 10.1.1.101

MS 10.1.1.102

Headspace unit: 10.1.1.103

  (everything under subnet mask 255.255.255.000)

 * you can check the IP that belongs to the instrument by pressing the "options" button on GC or HS unit and selecting "network". For MS you need to hit "menu" until you get to the "network" selection and hit "item" button to select.

 For me the computer IP got changed when I allowed the PC to automatically obtain an IP address to get network connectivity. I was able to remedy it by doing a windows recovery to before I allowed this IP change (I didn't know what the IP address needed to be at the time or else could have fixed it by manually changing the IP address back to 10.1.1.1). We now have separate network cards (1 for the GC modules and 1 for the network) and therefore 2 different IP addresses on the PC. Even though the correct IP is set for the LAN connection I still have to disconnect the physical ethernet cable for the network when starting chemstation otherwise chemstation defaults to using the network IP for the connectivity check instead of the IP address on the LAN network card connected to the instruments (thus it does not find them and errors out), otherwise I get the error " MS already in use by another session".

If you have the dynamic IP address option enabled in the instrument modules you are then outside of my scope of experience.

Good luck!

I ran into this same issue when trying to set up our GCMS computer for network access. For our system the modules were communication on predefined IP addresses (which I found out latter) The pc needed to be at IP 10.1.1.1 under subnet mask 255.255.255.0 in order for chemstation to pass its communication check on opening, otherwise the check would fail and the software would close. I believe by default the system (agilent 7980A GC) is set up this way. When you start chemstation it will ping each IP for the separate modules you have. Take note of what is says the IP addresses for the different modules are. You can check what the actual IP address for each module isFor us (on LAN connection with modules) the IP address for modules are as follows:

PC 10.1.1.1

GC 10.1.1.101

MS 10.1.1.102

Headspace unit: 10.1.1.103

  (everything under subnet mask 255.255.255.000)

 * you can check the IP that belongs to the instrument by pressing the "options" button on GC or HS unit and selecting "network". For MS you need to hit "menu" until you get to the "network" selection and hit "item" button to select.

 For me the computer IP got changed when I allowed the PC to automatically obtain an IP address to get network connectivity. I was able to remedy it by doing a windows recovery to before I allowed this IP change (I didn't know what the IP address needed to be at the time or else could have fixed it by manually changing the IP address back to 10.1.1.1). We now have separate network cards (1 for the GC modules and 1 for the network) and therefore 2 different IP addresses on the PC. Even though the correct IP is set for the LAN connection I still have to disconnect the physical ethernet cable for the network when starting chemstation otherwise chemstation defaults to using the network IP for the connectivity check instead of the IP address on the LAN network card connected to the instruments (thus it does not find them and errors out), otherwise I get the error " MS already in use by another session".

If you have the dynamic IP address option enabled in the instrument modules you are then outside of my scope of experience.

Good luck!