The Elekta Neuromag Vectorview and Triux scanners have a combination of magnetometers and two planar gradiometers at each sensor location.

This is further detailed in the Elekta System Hardware Users' Guide and on this page.

The following code demonstrates how you can determine the orientation of the two planar channels at each location.

grad = ft_read_sens(filename, 'senstype', 'meg');

sel = find(strcmp(grad.chantype, 'megplanar'));

for i=1:numel(sel)
  j = sel(i);
  clear coilindex*
  coilindex1 = find(grad.tra(j,:)>0)
  coilindex2 = find(grad.tra(j,:)<0)
  pos(i,:) = (grad.coilpos(coilindex2,:) + grad.coilpos(coilindex1,:))/2;
  ori(i,:) = grad.coilpos(coilindex2,:) - grad.coilpos(coilindex1,:);
  ori(i,:) = ori(i,:)/norm(ori(i,:));
quiver3(pos(:,1), pos(:,2), pos(:,3), ori(:,1), ori(:,2), ori(:,3))
axis equal
axis vis3d