Connect the drums to the Tascam recorder using 1/4-inch cables. Electronic drums may have a variety of outputs, from a stereo mix to individual drum outputs. Most Tascam units have small total track counts, so you may wish to use the stereo mix to keep free tracks open. Using individual outputs will give you more control of drum sounds when mixing.
Adjust the tone and balance of the drum sounds at the electronic drum sound module. Turn off compression and reverb unless it is critical to the raw sound you want. Both parameters are best left to the mixing stage for addition, so that the drum sound can be evaluated in context of the other instruments. Additions can be made; subtractions cannot.
Record the performance with the electronic drums. Watch carefully for drum signal peaking, particularly on a digital Tascam. Tape-based units are more forgiving.