In some cases when reconfiguring devices in the MPI utility in SCO OpenServer the old device nodes are not removed from /dev. This results in the inability to assign a particular letter to the devices for Xem, C/X and EPC/X products. To resolve this, the old devices should be removed from /dev. This includes the upper and lower case devices. Please use caution when removing these devices, removing devices other than the ones not needed could result in serious damage.

For example, you need to assign a 'b' ttyb01 through ttyb16 on your second module/concentrator and it is not listed as being available through MPI, you will need to remove them from /dev:

# cd /dev
# rm ttyb*
# rm ttyB*
# rm prb*
# rm prB*

Now the letter b will now show in the MPI list for available letter assignments.