PowerLabs provide power and communication to ADInstruments Front-Ends via an I2C connection. It is possible to use multiple Front-Ends with one PowerLab by "daisy-chaining" the Front-Ends as shown in the image below.
When you are using multiple single channel Front-Ends, you can use as many Front-Ends as channels on your PowerLab, and the Front-Ends can be daisy chained in any order. However, when using at least one multiple channel Front-End such as a Dual Bio Amp or Quad Bridge Amp, the order of Front-Ends in the daisy chain must be carefully considered.
Each PowerLab has a fixed number of I2C slots. When a Front-End is connected to the PowerLab, it uses up a certain number of slots regardless of the number of used inputs. For example, an Octal Bio Amp will use up 8 slots even if you will only be using 1 input of the Front-End. If you are connecting two Octal Bio Amps and a Neuro Amp to a 16-channel PowerLab, be sure that the single-input Neuro Amp is not the last Front-End in the daisy chain, otherwise the Octal Bio Amps will use up all of the I2C slots and the Neuro Amp will not work properly.