I want to transition from one note to another note very smoothly (portamento effect). So I am using two layers do accomplish this.
In first layer, I will play one note (default quarter duration) and then give silence (so that playing is not stopped)
In the second layer, I will go for pitch bend and gradually increase the pitch bend value in a loop to maximum of 1 semitone

Default duration = 0.25
Pitch bend depth = 1 semitone (set using #CC6, #CC100 and #CC101)
So pitch bend of 8192 = 1 semitone
Number of steps = 250
Pitch wheel value per step = 8192/250
Duration of each step = 0.25/250

So ina loop, I am increasing PW in steps of 8192/250 and each step is of 0.25/250 duration. I am getting the effect correctly.

Now my question is, what is the minimum duration required so that MIDI controller is able to play? Where can I find the spec? If I go for 300 steps (duration = 1/1200), I do not see pitch bend effect. So I guess it is because the duration is too small.

Example code (using Jfugue Library) for those who are familiar with JFugue music library.

Player player = new Player();
Pattern pattern = new Pattern();
pattern.add(" T100 V0 L0 I40 :CON(100,0) :CON(101,0) :CON(6,1) C R3 L1";
int PW = 8192; // Default Pitch Bend
int steps=250; // Let us consider 250 steps in one semitone
double duration = 0.25/steps; // Duration of each step
int PWValue=8192/steps; // This is the value of pitch bend to be changed gradually
for(int i=0;i<steps;i++) // S1 to R1
{
PW=PW+PWValue;
pattern.add(" R/"+duration +" :PW("+PW+" ";
}
player.play(pattern);