Remember that the 'C' programming language lets assign one struct to another; eg,

struct s
{
   bytes[5];
} myStruct;

myStruct volume_disp;
myStruct counted_pulses;

volume_disp = counted_pulses; // efficiently copies the data!

This will copy the contents of 'counted_pulses' into 'volume_disp' - and Keil C51 will generate very efficient code to do it!
(I looked into this a while ago).