Bizarre LCD display problem

[Joel Moore]

We just bought a T100MD888+ starter kit along with the MD-HMI interface and as soon as I powered it up I started seeing strange things on the display.

It looked like there was supposed to be some sort of default welcome screen with a clock and some other stuff but many of the characters where wrong--to the point where it was almost unreadable.  I was hoping it was just a corrupted program or something.

But now I think that something is faulty.  I created a test program that printed screenfulls of each printable ASCII character and it's pretty obvious that something is wrong.  Every other character in the ASCII set had problems.  By that I mean characters with an odd ASCII code printed fine while those with even ASCII codes had trouble.

Has anyone else seen this or should I just arrange for an RMA and get a new HMI or PLC?

[support]

Did you connect the small signal booster board in between the expansion cable and the HMI? The signal booster board is to provide a boost to the expansion signal to take care of the impedance of the the long HMI cable that is plugged into the expansion port.  The signal booster board and the installation diagram is provided with the HMI packaging. Furture version of T100MD+ will include the booster signal on board so that the booster board is unncessary. If the booster board doesn't solve this problem then you can contact us at 877-874-7527 to arrange for a replacement

[Joel Moore]

Thanks.  Despite thinking that board was only necessary if I had to use a cable longer than the one you supplied I still should have tried it.  I had forgotten about it.

I guess I'm still confused as to why that board affects the LCD display.  I was under the impression that the LCD was controlled entirely from the LCD port while the expansion port was only for the buttons.

Regardless, it seems to work now.  Thanks again.