I've got a breadboarded device that talks RS232 to a keyspan 232-to-USB converter to a G4 running X.4.11 . The device only talks and you can listen to it in a c program as /dev/tty.USA28X91P2.2 19200,8N1. I think I've configured it correctly in the NI-VISA configuration (pictures 1,2). My simple Labview vi (picture 3) fails with 1073807343. The serial examples fail as well with the same error, though both resource name ASRL1::INSTR and alias "serial_port_test" show up on the dropdown lists-before-excecution. Maybe I've got the "dev/..." syntax wrong in the dialog.
TIA
Alex