  We consider a discrete model of planar elasticity where the particles, in the
reference configuration, sit on a regular triangular lattice and interact
through nearest neighbor pairwise potentials, with bonds modeled as linearized
elastic springs. Within this framework we introduce plastic slip fields, whose
discrete circulation around each triangle detects the possible presence of an
edge dislocation.
  We provide a $\Gamma$-convergence analysis, as the lattice spacing tends to
zero, of the elastic energy induced by edge dislocations in the energy regime
corresponding to a finite number of geometrically necessary dislocations.
