Number of variables exceeds number of equations

First of all,Happy New Year! Wish u guys a good start in 2014~

I'm a newcomer here.In simlation of a simple closed circuit hydraulic system encouter I this error "Number of variables exceeds number of equations. Check for missing reference node." I dont know what's wrong, i'd be so grateful if u help.

[Walter Roberson]

It is not clear to me what your inputs and outputs of the solver are, nor what equation is being solved ?

[Liu]

my inputs are C port(3e-6),S port(188),ouput is the torque output from the variable displacement motor. Although C and S are constant values, can i still get one torque value from the motor, am i right?

i want to simulate a closed hydraulic circuit,with one varaible displacment pump and one two-displacement motor,and the pump S port should be the engine's velocity, but that's too complicated for me ,so i decide to make a simple simulation first.

Answer 1

[Liu]

Dear Walter Roberson，

I have a few things corrected,and it works well,Thank you so much!