Strange HMI object problem.

Have a problem that I have not ran into before on an HMI screen. Thought I would ask and see if anyone else has had this before. I have a Weintek 3105p HMI screen, connected to a 5370 E33 micrologix PLC. I have been using it for almost 4 months, today a bit lamp object went high,(turned on) and it has no power to it, the input on the PLC that the tag is addressed to is not on nor does it have voltage. I deleted the bit lamp object and recreated it and it still goes high. I unplugged the IT cable from the hub and the bit still goes high it the HMI screen. I can invert the signal to the bit lamp object and it turns of however it will not work when it goes high. Any of you more knowledgeable techs out there ever ran into this before? If so let me know this one is driving me crazy, plus I'd like to know what it is. I have tried everything my years of experience has taught me but failed to put my finger on the cause.

oldnerd said:

...I have a Weintek 3105p HMI screen, connected to a 5370 E33 micrologix PLC...

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Can we start by clearing up exactly which controller you are using?

"5370" refers to the newer range of CompactLogix controllers, not MicroLogix controllers.

"E33" is not an Allen Bradley controller I know of but I'm suspecting that you might be referring to an "L33ER" or similar?

Which controller you are using might be very important here as we try to get to the bottom of your problem, or misunderstanding.

The CompactLogix platform uses the more advanced RSLogix 5000 or Logix Designer for programming.

The MicroLogix controllers use the lesser RSLogix 500 for programming.

So what exactly have you got?

A full controller catalog number off the side sticker would be ideal.

Example CompactLogix controller...

1769-L33ER

In the meantime, I'm not familiar with programming the Weintek HMIs, but I'm sure someone else will most likely chime in.

Regards,
George

oldnerd said:

...today a bit lamp object went high,(turned on) and it has no power to it, ...

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Do you mean the PLC input has no power and your HMI is monitoring the input directly? There have been other threads with similar problems that changing the HMI so it does not look at any input or output directly solved. I always have the status of an input or output that I want the HMI to monitor mirrored to a bit by the PLC & monitor that bit.

...I unplugged the IT cable from the hub and the bit still goes high it the HMI screen....

Click to expand...

Could the HMI be set to default of the bit high? If it can't read the bit status for some comm reason it may go to the default setting.

Yes the HMI looks directly at the input bit at the PLC.

Then what I would do is add a line in the PLC:

Input''''''''''''''''''''''''''''''''''''NewBit
-||-------------------------( )-

And have the HMI look at NewBit, not the input

Thanks will try this when I can, doing this by VPN and the only time I can get in is when they are not running production.

George,
I'm new so bare with me. I have ran into something I can not figure out why it does this, need some help from the experts.
I have a AB 1769 L33ERM processor with two 1769-IQ16 input modules and two 1769-OB16 output modules. My boss is cheap so he would not buy a PanelView HMI, so I wound up with a Weintek 3105P HMI screen. This was bought from Rohtek and there is no tech support to speak of. Our customer has been running this machine for about four months with no problem. A few days ago the bit lamp on the control screen to tell the operator the e-stop has been pressed came on with out the e-stop being pressed. I had there electrician check the PLC input for voltage and it was at 0 volts. The led for the input on the module was off. I VPN into it and look at the tag in the processor and it was at 0. I went into the HMI software and deleted the bit lamp and re-created it, as soon as I boot up it comes on like the bit from the PLC was on but its not. So I go back and set the bit lamp object to invert the signal it goes off but when the bit in the PLC goes high (pressed the e-stop) it does not come on. The circuit is very simple the e-stops go to the AB safety relay, when the relay is not happy I have a 24 v signal to the PLC input, the HMI bit lamp object turns on when it sees this tag come on. I hope I have been descriptive enough for all to understand, if not let me know and I will try to do better. Thanks for the help in advance.

No, no - don't bare with us: we don`t need any naked bodies here. We'll bear with you

Is it possible that the input is fluctuating rapidly and the HMI lamp just can't keep up? So far adding a rung with the real input to an internal bit, then monitoring the bit seems a good test.

Every one thank you for the help. I created a rung in the plc with the input bit and a output to the HMI bit lamp, bingo problem solved. Learned something on this one. Thanks Abeck it worked.

It doesn't make sense or seem possible, but it happens (too much) that when a HMI looks directly at an input or output it falsely shows it ON, never falsely showing it OFF.