Multi-unit Recording Option

It is possible to record more than one unit simultaneously with the FF program. The multiple units must be available as separate inputs to the UET (Unit Event Timer). FF cannot separate multi-units if they are connected to the same UET input.

Use the following steps for multi-unit recording with FF:

(1) Specify the UET channel numbers to be used as follows:

          $ DCP
            MODE FF
            SET SPIKE CHAN 0 4 5    (for example)
            XP FF

In the above example, we specify that spikes on UET channels # 0,4 and 5 be recorded and stored by FF. You may wish to place the "set spike chan ..." command in the same DCP macro that starts FF, so there is no need to type it each time.

(2) Proceed with FF data collection as usual. Event times from any spikes on channels 0,4 and 5 (e.g.) will be automatically stored with any data saved by FF.

(3) The "set spike chan ...." command, once issued, stays in effect unless another "set spike chan ...." is issued to change it, even if the program exits or if the machine is rebooted.

(4) If you wish to record data from channel 0 alone (e.g.) then either repeat step (1) above using "set spike chan 0", or simply disconnect any input to UET channels other than 0.

(5) The UET channel numbers enabled by FF are displayed for informational purposes as a legend in the upper right-hand corner of the coordinate grid display.

(6) UET channel numbers 2,3 and 6 are reserved for special purposes and cannot be used for event timing.

At present (Sep. 1998), FF does not record the UET channel selections within each dataset. It does, however, record this within the log-file that is created each time that FF is started.

For analyzing multi-unit data, use the RAP command "set spike chan # # .." to select one or more channel to include in subsequent analyses. To select all UET channels in RAP, use "set spike chan all", which is also the default.