05-21-2009 09:00 PM
I'm trying to find the problem node in my circuit. But I have no idea how to read the error list that multisim gives me. Can someone help me? This is what I keep getting.
Instrument operation performed (2009, May 21, Thursday, 19:58:20)
| Instrument Analysis: Transient Analysis
| | Plot title:
| | Analysis settings
| | | Initial Conditions: Zero initial conditions
| | | Starting time (TSTART): 0
| | | Stop time (TSTOP): 1e+030
| | | Plotting increment (TSTEP): 0.001
| | | Maximum time step (TMAX): 0.001
| | Perform consistency check
| | Variables from analysis
| | | Show device values at the end of the simulation
| | Representation as SPICE commands
| | | begin-scope page
| | | checknodes 3
| | | save all
| | | iplot all
| | | set reltol = 0.01
| | | set trtol = 7
| | | set itl4 = 100
| | | set method = "gear"
| | | set ramptime = 0
| | | set convlimit
| | | set rshunt = 1e+009
| | | -param hrange 0 1e+030
| | | save
| | | tran -env-options 0.001 1e+030 0 0.001 zero_ic
| | | if-error end-scope audit-log-show
| | | show all
| | | showmod all
| | | end-scope
| | Custom Analysis Options
| | | Relative error tolerance: 0.01
| | | Truncation error overestimation factor: 7
| | | Upper transient iteration limit: 100
| | | Integration method: gear
| | | Transient analysis supply ramping time: 0
| | | Enable convergence assistance for code models
| | | Shunt resistance from analog nodes to ground: 1e+009
| Output from instrument analysis
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0 (How do I read this?)
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | singular matrix: check nodes adac1in:xu2.o0#branch_1_0 and adac1in:xu2.o0#branch_1_0
| | TRAN: Timestep too small; initial timepoint: trouble with (led_mod:xled1) d1:xled1
| | doAnalyses: timestep too small
| |
| |
| | tran simulation(s) aborted
05-28-2009 07:47 PM
A singular matrix can arise for a few reasons - sometimes with floating nodes (internal to model or at circuit level) or with inductor components. Is it possible to post the circuit in question?
adac1in:xu2.o0#branch_1_0
This line refers to an instrument or component connection on U2 (adac1in is likely internal to the model) - usually a #branch is a SPICE designation to force/analyze current going through a node (SPICE tries to calculate the current/voltage at each node at each time step), thus the error is stating that the Multisim SPICE engine cannot correctly calculate this in this part of the SPICE netlist. I believe you are getting several errors because SPICE tries to automatically change the time stepping (in an attempt to solve for a solution based on SPICE engine settings) and will eventually stop if unsuccessful.
If we can analyze the circuit, we'll have a better idea what is going on.
Regards,
Patrick Noonan