If you are using a multi-channel amplifier from ADInstruments (Quad Bridge - FE224, Octal Bridge - FE228 or Octal Bioamp - ML138), it is NOT possible to split the channels between 2 or more PowerLabs.
ADInstruments Front-ends including these amplifiers, are configured using the I2C
cable connected to the PowerLab. Only one PowerLab can have this
connection to a Front-end so any front-end channels connected to
another PowerLab can not be detected by LabChart and can not be