  We present a scalable method for the control of ion crystals in a grid-based
surface electrode Paul trap and characterize it in the context of transport
operations that sort and reorder multispecies crystals. By combining co-wiring
of control electrodes at translationally symmetric locations in each grid site
with the site-wise ability to exchange the voltages applied to two special
electrodes gated by a binary input, site-dependent operations are achieved
using only a fixed number of analog voltage signals and a single digital input
per site. In two separate experimental systems containing nominally identical
grid traps, one using $^{171}\mathrm{Yb}^{+}$-$^{138}\mathrm{Ba}^{+}$ crystals
and the other $^{137}\mathrm{Ba}^{+}$-$^{88}\mathrm{Sr}^{+}$, we demonstrate
this method by characterizing the conditional intra-site crystal reorder and
the conditional exchange of ions between adjacent sites on the grid. Averaged
across a multi-site region of interest, we measure sub-quanta motional
excitation in the axial in-phase and out-of-phase modes of the crystals
following these operations at exchange rates of 2.5 kHz. These conditional
transport operations display all necessary components for sorting qubits, and
could be extended to implement other conditional operations involving control
fields such as gates, initialization, and measurement.
