Hi Experts,
Here is the problem, a HMI is communicating with a S7-300 system over an ethernet connection (using ISO TCP/IP Protocol). The scan time in the PLC is rather high (50 - 70 ms). The HMI updates slow when the scan time is high but if we download a simple PLC-application (with a low scan time) then the communication/update is OK.
I assume that the problem is caused due to that the PLC only answers to HMI's requests in the end of the scan cycle. I'm more familiar with Mitsubishi PLC-systems, and Mitsubishi Q has a function called COM_M that you can add in the ladder, this function will make the PLC answer requests directly (and not in the end of the scan cycle).
So, the question is, are there any settings/functions in the S7-300 that will improve how the PLC handle requests from the HMI? All ideas and suggestions are most appreciated.
Thanks,
//Supporter
Here is the problem, a HMI is communicating with a S7-300 system over an ethernet connection (using ISO TCP/IP Protocol). The scan time in the PLC is rather high (50 - 70 ms). The HMI updates slow when the scan time is high but if we download a simple PLC-application (with a low scan time) then the communication/update is OK.
I assume that the problem is caused due to that the PLC only answers to HMI's requests in the end of the scan cycle. I'm more familiar with Mitsubishi PLC-systems, and Mitsubishi Q has a function called COM_M that you can add in the ladder, this function will make the PLC answer requests directly (and not in the end of the scan cycle).
So, the question is, are there any settings/functions in the S7-300 that will improve how the PLC handle requests from the HMI? All ideas and suggestions are most appreciated.
Thanks,
//Supporter