ADInstruments have a range of Front Ends or Signal Conditioners known as Pods which connect to the PowerLab via the 7-Pin DIN inputs.
It is not possible to split the signal as you might with a BNC input. However, if you are using one of the Research PowerLab series (SP, 30 or 35 series or later), it is possible to output the Pod signal via the associated BNC connector on the PowerLab as the DIN pod ports and BNC inputs are internally linked.
So for example, you would attach the Pod to the DIN input on Channel 1 and then connect a BNC cable from the BNC connector on channel 1 to the external analogue recorder.
NB If you are using a Pod expander, the BNC outputs on this unit can be split using a T-piece between the PowerLab and the other anaolgue recording device.
For further technical assistance with this or any other issue, please contact ADInstruments Technical Support by clicking HERE.