If g_pas were GLOBAL, it would be sufficient to drive g_pas in just one section; then g_pas in all sections that have the pas mechanism will follow the same time course. But g_pas is not GLOBAL, so you have to drive it in each and every section in which you want it to follow that time course.

I have tried to have a seperate file for each instance

No need to do that. A single pair of vectors that define a waveform can be used to drive as many variables as you like.

I have an imported vector which has the same time-step dt as that set in my hoc code

An ordinary linear ramp can be specified with a much smaller number of points. Consider a ramp that starts at t=0 with value a and remains constant until time t1.

Over the interval t1..t2 it sweeps from a to b.

After t=t2 it remains constant at b.

Just make a vector tvec whose elements have these values

0

t1

t2

t2+1

and another vector yvec whose elements have these values

a

a

b

b

and then use Vector play with interpolation to make yvec drive whatever variable you wish.

The idea is to treat the driving function as a piecewise linear function. You only need to specify the t,y coordinates of the first point in the waveform, then the coordinates of subsequent points at which slope changes. Finally you need to end the tvec and yvec vectors with the coordinates of one last point that, with the penultimate point, defines the slope of the waveform as t->infinity.

In addition to being very compact, this has the advantage of working with adaptive integration or with fixed time step integration regardless of the value of dt. (of course if you're using fixed time step integration, you'll want your function's breakpoints to occur at times that are integer multiples of dt).

Another example: this pair of vectors specifies a rectangular pulse of amplitude 1 that rises from a baseline of 0 at t1 and falls back to the baseline at t2:

tvec

0

t1

t1

t2

t2

t2+1

yvec

0

0

1

1

0

0

Notice that each discontinuity in a function is represented by specifying two points "at the same time" such that the first specified point's y coordinate is the function value just before the discontinuity and the second specified point's y coordinate is the function value immediately after the discontinuity.