code: def setSystemVariable(self, remote, name, value):
          
          if self.remotes[remote]['username'] and self.remotes[remote]['password']:
              LOG.debug(
                  "ServerThread.setSystemVariable: Setting System variable via JSON-RPC")
              session = self.jsonRpcLogin(remote)
              if not session:
                  return
              try:
                  params = {"_session_id_": session,
                            "name": name, "value": value}
                  if value is True or value is False:
                      params['value'] = int(value)
                      response = self._rpcfunctions.jsonRpcPost(
                          self.remotes[remote]['ip'], self.remotes[remote].get('jsonport', DEFAULT_JSONPORT), "SysVar.setBool", params)
                  else:
                      response = self._rpcfunctions.jsonRpcPost(
                          self.remotes[remote]['ip'], self.remotes[remote].get('jsonport', DEFAULT_JSONPORT), "SysVar.setFloat", params)
                  if response['error'] is None and response['result']:
                      res = response['result']
                      LOG.debug(
                          "ServerThread.setSystemVariable: Result while setting variable: %s" % str(res))
                  else:
                      if response['error']:
                          LOG.debug("ServerThread.setSystemVariable: Error while setting variable: %s" % str(
                              response['error']))
  
                  self.jsonRpcLogout(remote, session)
              except Exception as err:
                  self.jsonRpcLogout(remote, session)
                  LOG.warning(
                      "ServerThread.setSystemVariable: Exception: %s" % str(err))
          else:
              try:
                  return self.proxies["%s-%s" % (self._interface_id, remote)].setSystemVariable(name, value)
              except Exception as err:
                  LOG.debug(
                      "ServerThread.setSystemVariable: Exception: %s" % str(err))
docs: Set a system variable on CCU / Homegear