We study three-dimensional supersymmetric quiver gauge theories with a
non-simply laced global symmetry primarily focusing on framed affine BN
quiver theories. Using a supersymmetric partition function on a three sphere,
and its transformation under S-duality, we study the three-dimensional ADHM
quiver for SO(2N+1) instantons with a half-integer Chern-Simons coupling. The
theory after S-duality has no Lagrangian, and can not be represented by a
single quiver, however its partition function can be conveniently described by
a collection of framed affine BN quivers. This correspondence can be
conjectured to generalize three-dimensional mirror symmetry to theories with
nontrivial Chern-Simons terms. In addition, we propose a formula for the
superconformal index of a theory described by a framed affine BN quiver.Comment: 39 pages, 7 figure