ADS瞬时仿真时出现ERROR

用ADS进行瞬时仿真时，出现下述的错误，这是我copy的仿真文件叙述
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    Matrix is singular (detected between nodes or branches `X6218.L1.i' and `X5906.L1.i').
Error detected by HPEESOFSIM during DC analysis `Tran1'.
    Circuit as given has no unique solution。Warning detected by HPEESOFSIM during TRAN analysis `Tran1'.
    Matrix is singular (detected between nodes or branches `X359.L1.i' and `X670.L1.i').
Error detected by HPEESOFSIM during TRAN analysis `Tran1'.
    Matrix is singular (detected between nodes or branches `X540.L1.i' and `X982.L1.i').
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X737.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X6334.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X6314.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X344.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X5518.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X650.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X11290.L1.i.
Warning detected by HPEESOFSIM during DC analysis `Tran1'.
    A virtual resistance of 1 pOhms
    was added to branch X635.L1.i.
Error detected by HPEESOFSIM during DC analysis `Tran1'.
    No DC convergence.
        To search for a more robust convergence algorithm,
        set ConvMode=1 on the DC analysis and perform the DC
        simulation again.  This will cause the simulator to vary
        the convergence parameters and report which parameter
        setting produces the fastest convergence.
Status / Summary  
HPEESOFSIM (*) 2003A.300 Apr  9 2003 (built: 04/09/03 22:50:55)
Copyright Agilent Technologies, 1989-2003.
.................
Perform Pseudo-Transient analysis
..
Error: Circuit Failes to converge at node `_net350649'
-------------------------------------------------------------------------------
Simulation finished with errors.
当中提到要把ConvMode=1，可是我没有找到在哪里设置这个参数
这个问题比较棘手，望达人赐教
多谢