C200HS & NT30C "Connecting to host" issue

[Fast_Eddie 0]

Good afternoon,

I have a little problem on my hands with some test units I have recently received. PLCs are very new to me.. and I'm learning quickly, so here is some background. I have five test units which are all identical in their control hardware (and I believe in software as well). The units run a SYSMAC C200HS PLC which feeds into a NT30C-ST141B-E HMI. On boot up, three (3) of the test units display "battery lowered" on the first screen.. then it switches to a "connecting to host" screen and stays there. They never leave the "connecting to host" screen. 

I went through both the PLC and HMI on each unit and found the HMI's battery was indeed dead. So I replaced that and the units no longer say "battery lowered" and now only shows the "connecting to host" screen. 

What's interesting is that the other two (2) units that did not have battery trouble booted right up and opened the home screen of the HMI and allowed me to program and run the test unit as it should. None of the five (5) units have received any programming work or changes since they ran last.. simply a long period of dormancy during which some of the units' HMI batteries died.

So I my question is this.. would letting the battery deplete and then replacing it with a fully charged battery cause issues "connecting to host" and if so, where would I start in my trouble shooting process? I am open and grateful to hear any advice on this topic and input you may have based on my situation.

Thank you in advance,

Ed

[gtsuport 61]

Replacing the battery would not cause this issue.

If you touch the upper left and lower right corners of the screen, it should go into the built in menu.

Guessing the depleted battery has lost the program in those units.  You should be able to pull the program from a good unit and load into the ones not connecting.

Also, you should check the battery in the C200HS units as well.

gtsuport

[IO_Rack 181]

Connecting to Host means a communication issue. The batteries in the NTs are for the Real Time Clock. The program is stored in flash memory so a battery is not necessary.

As Gtsuport has suggested, go to the system menu and make sure the communication settings match the PLC.

***EDIT***

Just checked the manual. The program is not lost but the Memory Switch settings are lost by a dead battery. This means the communication settings have been initialized to default. So yes, this caused your issue. 

We used to run NT20s without batteries. Not sure if it was because they were not required or because we ran with default settings. Too long ago.

Edited 20 Jul 2021 by IO_Rack

[Fast_Eddie 0]

Thank you gtsuport and IO_Rack, I appreciate your information! I will be spending time on this today and will let you know my findings/hopeful success!

Thanks again,

Ed