need to fetch unique values in a column

we really need some sample data and any code you have available.

Assuming that table is a data.frame, then off the top of my head you should be able to do

unique(mydata$circuitid) 

where your data.frame is mydata
to get the unique ids and then

dat1   <-  subset(mydata, circuitid ==  "SAB00001680")
```