|No. 1643||Re: CIE-H10 Modbus Notification||2019-03-20|
Generally, in Modbus/TCP, Master periodically send request to Slave. Slave send its state in the response to Master. It means that if Slave want to send the state to the Master, It MUST wait for request from Master.
Therefore, if input of Slave changes and then changes back to old state in short time ( < polling interval of Master), the state of input is sent to Master are the same as previous update. Therefore, we feel that the state is not sent.
For example, polling interval is two seconds, input change from LOW -> HIGH, and then changes HIGH -> LOW. the time interval between two changes is one second. In this case, state of input is sent to master is still LOW. Therefore, we feel that state is not sent, but actually it is sent with the same value as the previous update.
In CIE-H10, we have an option that allows Slave send state immediately after state changed WITHOUT waiting for request from Master. This option call "Notify Input Port Change". The option is disabled by default. You can enable it via ezManager software.
If you have any further question, please feel free to ask us!
> DE CARVALHO wrote:
> I use CIE-H10 (v2.0a) module with Modbus/TCP (Slave mode) and IP Active connection to a peer. Sometimes the CIE-H10 stops sending input change notifications. The input led state change, the Socket is OK and writing to output works fines.
> What is the problem ?