Recently I watched a video explaining communication protocol IEC 60870-5. The video states that the General Interrogation (GI) command takes the following sequence
- Master Station sends an interrogation command
- Controlled station responds by sending an acknowledgement.
- Controlled station sends all its process data to master following the acknowledgement signal.
- Controlled station sends an end of message signal.
I am working in SCADA in a power utility company in Pakistan. We were facing a problem that master station was not receiving data in response to GI command. An engineer of Siemens solved the problem by configuring the Remote Terminal Unit (RTU) to not send an acknowledgement. I would like to know what are the disadvantages of opting this solution? Why acknowledgement is sent by slave or RTU in response to GI in IEC 60870-5 protocol?