1. In a system receiving digital signals with channels each having respective data receivers operated in at least one collection having at least two channels and their data receivers therein and wherein each collection shares in common a constrained sampling parameter value while each data receiver in a collection also has an independently variable unconstrained sampling parameter, a method of selecting the constrained sampling parameter value for a collection, the method comprising the steps of: (a) for each digital signal in a collection, making an eye diagram expressed as a series of sampled locations; (b) selecting for the constrained sampling parameter a common measurement axis and a common step size thereon to be used for identifying locations in each eye diagram made in step (a); (c) normalizing the eye openings of the eye diagrams made in step (a) to express the coordinates of their locations in units of Figure Of Merit related to performance parameters of their respective data receivers; (d) subsequent to step (c), assigning to each location within the normalized eye openings and in units of the Figure Of Merit of step (c), a Figure of Merit for the combination of normalized sampling parameters represented by such each location in the normalized eye openings; (e) making for each channel an ordered list, ordered by the Figure Of Merit assigned in step (d), of preferred combinations of normalized sampling parameters, each combination being a normalized constrained sampling parameter value and its associated normalized non-constrained sampling parameter value; (f) restating the sampling parameter values of the ordered, normalized, lists of step (e) in the same terms as used in step (b); (g) finding the most preferred entry for the restated constrained sampling parameter in each ordered list of step (e) that is shared by each channel; and (h) for each channel, finding the restated non-constrained sampling parameter value that is associated with its shared most preferred restated constrained sampling parameter entry found in step (g).