Due to stringent timing requirements of the WirelessHART protocol, we need to extend previously known hybrid simulation approaches with WirelessHART specific functionality. Because of intermediary devices that connect simulation and real environments a communication delay significantly exceeds time boundaries of a WirelessHART slot. Our solution is to add a WirelessHART-enabled intermediary device operating at the Physical and the Data Link layers that can handle time critical tasks of the WirelessHART protocol. This approach allows to evaluate the performance of a WirelessHART network and WirelessHART-enabled devices in a hybrid simulation environment.