Thank you for so detail answer, phildunlap. As for polls every second, is that mean TCP keep alive will consume less bandwidth than TCP? Any figure about that? Estimated need more bandwidth of 5% or 20% like that?

Compare with Modbuse IP Transport type TCP, how many bandwidth saved if use Transport type TCP, keep alive?

Thank you MattFox, I get it!

Thank you MattFox, phildunlap and Jared Wiltshire,
I searched the folder, and only found momentFilter.js, moment-timezone-with-data.js, moment-with-locales.js, moment-timezone-with-data.min.js, moment-with-locales.min.js, which one I should modify? Is that mean to replace "string" to "YYYY/MM/DD"?

How to change date format on chart x axis? I want to change "22 May" to "May 22" etc, is that possible?

thanks, phildunlap

thank you, JoelHaggar, i will look into it.
sorry, phildunlap, I mean Modbus IP TCP keep alive. it do not work. anyway, Modbus IP TCP work well.
I have a question, what's the speed limit for modbust IP poll interval? 1ms or 50ms or 500ms or 1 second?

by the way, I can't make modbus persist tcp to work, it just poll data one time when system restart, and then do not update anymore. so currently i use modbus tcp connection, it work well for one PLC.

I want to know whether mango can meet my project capacity request. I try free version, and connect to 1 PLC by modbus ip, to poll 20 points, and I set poll interval is 500ms, and log to database every 3 minutes, it running well, but CPU keep busy, most of time 80%~100% occupied, and harddisk also busy, keep lighting flash, bandwidth arround 200KB/S, my computer is i5, 8G RAM. so I worry about if mango is possible to handle 50 PLC (1000 points, each poll interval 500ms) by same time? does mango has ever tested about maximum capacity limit? any proposals for this? thanks

ok, I will try.