HI
every time I cycle power the cpu it does not come back to run mode and I have to connect it back to computer and put it in run mode. If the cpu is already in run mode and power is cycled then cpu is forced to go to run mode without connecting it to terminal what is my problem just to remind you that no error/fault indicated on cpu. Thanks

[quote name='MIKE31' date='May 26 2009, 11:59 AM' post='83473']

if the cpu is already in run mode and power is cycled then cpu is forced to go to run mode without connecting it to terminal

Hi,
Not sure i understand what you mean...
What is the PLC?
Do you use CXP? If yes, what is checked at: Settings / Startup / Mode ?

Omron PLC?
CX-Programmer?
See Attachment

Mike31,

Which processor unit are you working with?

Is there anything plugged into the peripheral port?

You may be able to force the desired mode on power up in the Settings or Setup area,
depends on processor and software.

Hope this will help.

If the startup mode is set to "use programming console" and -anything- like a CIF or hand programming tool is connected to the peripheral port on power on, it wil go to program mode. However if it is set to run using the programming tool, and the peripheral connector is unplugged and following a power cycle is performed, it will start in run mode. Very confusing if you are not aware of this...

Thanks a lot for the responses as you experts showed me how to resolve this problem .Now system is running OK. Highly appreciated Mike.

Hi PDL,

reading this topic I thought it might solve a problem that occurs from time to time with our PLC's.
We're using CJ1m CPU11 or CPU 12 and a NT3S is connected on the peripheral port, on the RS232 port is a GPRS-device connected.
The settings for the PLC's are "Monitor-mode" because we're executing commands over GPRS (i.e. Reset counters or changing values).
But some PLC's will change to Program-mode from time to time and then it will no longer respond to commands.
Is there a way to check in what mode the PLC is and if necessary correct this?

Thanks,

Carol

Hi Carol,

Do you mean a flag to check the mode in the PLC ladder or to check the actual startup mode setting?
You can check the startup mode setting on the main settings tab in CXP.
Connect to the CPU, open the settings tab and select Options > Transfer from PLC to be sure you are looking at the current setting.
In your case it should be set on Monitor. If it is set on Program or Use Programming Console it will cause the PLC to startup in program mode in case of a power failure.

FYI the serial port cannot influence the startup mode on power up. The use programming console option only affects the peripheral port.

Regards,

PdL

Edit: sorry Carol guess I need another coffee I overlooked you stated the setting already is Monitor. (you could of course double check with the Transfer from option)
The problem you have is that you perhaps might be able to detect which (running) mode the CPU is in, but if it is in stop there is no way yo can execute any kind of function to correct it as the code will not be scanned
In that case it is quite strange the CPU mode changes to program just like that. Does it happen on multiple systems at different locations?

PdL,

the PLC is by default set in Monitor-mode and every now and then it will change to Run-mode, this happens with a few PLC's on different locations.
These PLC's are programmed for telemetry purposes such as pupmpcontrolling. (sometimes combined with rain-measerument.)
A central post will recieve all data and resets the counters to zero at midnight.(Rain, electric consumption, starts and runtimes)
But when the PLC is in Run-mode, this command will not be executed. The central post will still collect the data, only now the data is cumulative.
So the question remains: is there a way (a flag in ladder / or some system-bit) to determine in wath mode the PLC currently is.
Then it would be possible to take action; when the central post reads the on/off state of such a flag it can send a command to push the PLC in Stop-mode and then restart the PLC.(this is now done manualy, once whe noticed the wrong Operating-mode)
When the PLC is restarted it is in Monitor-mode again, as it should be.

Hope this make any sense,

Carol

Carol

I am a little confused as to which mode the PLC is changing to:
1. Monitor Mode -> Program Mode
or
2. Monitor Mode -> Run Mode
or both???
I have never seen a situation where the PLC is changing modes by itself.

If the answer is 1 (Monitor to Program), then the there is not much you can do by programming in the PLC.
If the answer is 2 (Monitor to Run), then the PLC can handle this.

The PLC can monitor (via FINS commands) the operating mode.
If the PLC changed to RUN mode, the PLC could send itself a FINS command to go back to Monitor Mode.
This is a band aid fix, but does not explain the cause of the mode change. Poor power to the PLC???

So the question remains: is there a way (a flag in ladder / or some system-bit) to determine in wath mode the PLC currently is.

[/quote]


Hi Carol,
You could make your own flag: At first scan, Set a bit. The bit will stay ON as long as the PLC is in monitor or run mode.

PMCR

if the PLC changes mode it is from Monitor-mode to Run-mode.
How would such a FINS command look like?


pfort

Since the PLC changes state as described above, such a flag will do no good. In Monitor-mode as well in Run-mode this flag will be true.

Carol

Carol

Attached is a program that will detect RUN mode via FINS Command 0601, and change to Monitor mode via FINS command 0401FFFF02

Click to view attachment

PMCR

thanks, I'll look in to it, see if this is applicable in our applications.

Carol