We have siemens s7 300 PLC which is connected with Hitachi PLC through ethernet with CP343-1. When we connect another computer in that network, we can ping both siemens PLC and Hitachi PLC. But when we try to send data from the Hitachi PLC to siemens PLC we do not see any change in the data block in the siemens PLC. Could any body give me some suggestion ?