Modelname.Nodlim = x;

This attribute specifies the maximum number of nodes to process in the branch and bound tree for a MIP problem.  This can stop solutions that are exhibiting "excessive" iterations and if the limit is reached causes the algorithm to terminate, without reaching optimality.  The Nodlim parameter is specified as an integer.

Use of this parameter is done using a command like (secur.gms)

security.nodlim=10000;

where the model being solved is named security and nodlim is set to 10000.