Low level interface function to the IBM ILOG CPLEX function
  CPXdisconnectchannel.  Consult the IBM ILOG CPLEX documentation for
  more detailed information.
disconnectChannelCPLEX(env, newch)An object of class "'>cplexPtr" as returned by
    openEnvCPLEX. This is basically a pointer to an
    IBM ILOG CPLEX environment.
A pointer to the channel containing the message destinations as returned by
    CPXaddchannel.
NULL
Interface to the C function disconnectChannel which calls the CPLEX
  function CPXdisconnectchannel.
The IBM ILOG CPLEX home page at https://www.ibm.com/support/knowledgecenter/SSSA5P.