function [d,s]=liga(placa)
%   [d,s] = liga(placa)
%

if nargin<1,
    placa = 'Dev1';
end

d = daq.getDevices
s = daq.createSession('ni')
s.addAnalogOutputChannel(placa,'ao0','Voltage')
s.addAnalogInputChannel(placa,'ai0','Voltage')

return