Siemens HMI not showing machine values

I am using SIMATIC S7-300 314 CPU and my problem is I can't see the setpoints and process actual values on the HMI-it's displaying '####s'. Have changed the comms cable between the two but no joy!

There is one scenario giving me all I want though but dont understand it and can't run the machine that way:

When I connect my Programming Laptop (the Siemens PG)then I get the PLC and HMI comms machine ready to run i.e all the values appear and once I remove the DB9 from the PG or shutdown the laptop I loose comms between the PLC and the HMI.

I am not too familiar with Siemens. can someone help!

We once had a situation that looks like this. it involved a FB with instance DB. the DB was changed (some stat variables of the FB), but only offline. it would only work when you monitored the FB online.
So, not sure, but maybe... your online/offline block differs and the HMI is looking at an address that does not exist online. I think in that case your SF led should light.

Thanks wimpiesplc.

The PLC leds are shoeing that all is well and, i forgot to state it, this machine was running well before this issue came up. Is the addres you mentioned in reference to tags or IP Address?

this machine was running well before this issue came up.

Click to expand...

yeah, that's a killer.
anyway, I'm meant addresses in the used DB, like "DB9.DW0".
Did you did a compare between the online and offline blocks?

Yes I did a comparison with the backup file and all was the same except for one value which was an instantaneous value as compared from the time the backup was done and the present variables I thought!

tumbared said:

I am using SIMATIC S7-300 314 CPU and my problem is I can't see the setpoints and process actual values on the HMI-it's displaying '####s'. Have changed the comms cable between the two but no joy!

There is one scenario giving me all I want though but dont understand it and can't run the machine that way:

When I connect my Programming Laptop (the Siemens PG)then I get the PLC and HMI comms machine ready to run i.e all the values appear and once I remove the DB9 from the PG or shutdown the laptop I loose comms between the PLC and the HMI.

I am not too familiar with Siemens. can someone help!

Click to expand...

Check the terminating resistors.
On the Profi connectors you'll have a little red switch that engages/disengages the terminating resistor.
I assume since when you hook up the laptop, the terminating resistor on that cable is on no commas issues.
When you remove it, the terminating resistor on the existing connector is off.
Switch and test.

Thanks bkottaras but I have checked that too and even went as far as geting another new cable to verify the cable side as well as HMI of things. Tried the the same cable on another machine and its ok!

Really stuck!!!

You didn't say which HMI type.

Just a shot from the hip; could it be your HMI is not set as master, but only act as a passive listener?

Kalle

Its a SIMATIC MULTI PANEL 1P 6AV6 644-0AA01-2AX0 Type 4X/12. Not too sure about the setiting part but we have been using it as Master/Slave if tat mean seting process parameters as well as monitoring

As to the changing of cables, you can try with the white-grey direct cable (6ES7901-0BF00-0AA0). If that does not work, then it is not the cable that is the problem.

There are 4 small dip-switches on the rear of the panel. Be sure that they are set to "MPI/DP" and not "RS485/RS422".

Check in the Windows Control Panel on the panel, that the MPI/DP interface has not been disabled, or settings manually changed away from the proper ones.

Post all the settings or a screenshot for the connection setup in Protool or WinCC Flexible.

Hi Jesper,
I am at deadend now, the problem is my operation is more of AB systems and the Siemens we have (as u may know) are robust and thus less issues therefore there have been less interaction with this software and now we are all not clued up with say WinCC as much as I know it in word. Any other help as to get this info!

When you open the WinCC Flexible project, there is a project tree in the left side of the window. Navigate to Communication .. Connections.
Take a screenshot and post it here.

When you power up the Multipanel, for a short time it will display a menu where you can select Control Panel. Activate the Control Panel before the runtime program starts automatically. You only have a few seconds to do this.
A window with several small program icons will appear. Navigate to S7-Transfer Settings.

Follow the instructions in chapter 6.14 to see that the MPI/DP port has not been set to something else than then default (187.5 Kbaud). Otherwise than that, do not change anything, do not enable the MPI/DP port for transfer (use the ethernet port for that):
http://support.automation.siemens.com/WW/view/en/26248558

And check with a direct MPI cable, and check the dip switches as I suggested before.

Thank you everyone for the information! Put in a new CPU and everything was sorted. Machine still under warranty and we will be sending back the one we removed and it is to be redirected to Siemens, so i hope we will also get a feedback!

Thanks once again