The Control Layer is composed of several behavior modules that directly read sensor values and send reactive commands to the effectors based on the readings. The modules are similar to the Augmented Finite State Machines of Subsumption Architecture because of their fast stimulus-response nature. Likewise, they have only ephemeral state.
The stimulus-response mapping is mediated by the Sequencing layer, which gives it commands in ALFA (A Language For Action), a language similar to REX.