Commonly Asked Questions; Black Screen After Download - KEP MMI-1500 Installation & Operation Manual

4.3 Commonly Asked Questions

Q. Can I have multiple MMIs connected to one Controller?
A. The ability to connect more than one HMI to a controller is accomplished through an HMI to HMI link. This is not
done through any PLC protocol. It is done through the master-slave protocol of the MMI.
Q. How do I call up windows with my PLC?
A. Use the PLC Control part configured as "Change window" to call up windows by word value. Additionally, Direct
and Indirect Window parts can be used to bring up windows.
Q. Do I need to change any jumpers to go from one Controller type to another?
A. No, the driver that is downloaded into the unit at programming time determines the Controller type. The dip
switches on the back of the unit should all be in the OFF position.
Q. Is there any way to completely erase the HMI user memory?
A. No, the HMI memory is initialized automatically before every download cycle.
Q. How Do I change the Battery?
A. Battery replacement requires disassembly of the unit in an ESD controlled environment. Battery life expectancy
is greater than 5 years.
The MMI-7XX takes one coin type of CR2032 lithium battery to backup the recipe data and keep the RTC
running. Battery specification: CR2032 3V lithium battery.
Steps for battery replacement:
1. Use EasyManager to backup the retentive memory data.
2. Turn off the HMI and remove its rear cover.
3. Remove the battery from the socket.
4. Insert a new battery into the socket.
5. Put on the rear cover.
6. Reset the RTC time and download the retentive memory data.
The MMI-850 and 1500x products have the battery soldered to the main board. We recommend that these
units be sent back to the factory for battery replacement.
Q. Can I change the Backlighting bulbs in the field?
A. We recommend that the unit be sent back to the factory for bulb replacement. Backlight bulb life expectancy is
greater than 5 years even if running 24 hours a day. Use the Backlight auto shutdown to conserve backlight bulb life.
Q. Why am I getting slow updates on my windows?
A. PLC communication speed controls the update speed. Try using a higher baudrate and adjusting the Block pack
settings. If an overloaded window is causing a slow update, we suggest changing the window design.
NOTE: EasyWindow has a tool called "SystemResource". It displays object queue item numbers. Use this to help
detect communication problems. This problem might not show up in Offline Simulation because the PC may have
more CPU speed, more caches, and more VGA speed.
4.4 Hardware Problems

4.4.1 Black Screen after download

Symptom: After project downloaded to a new touchscreen a blank black screen is displayed.
Cause: Using the older versions of EasyBuilder to download to newer model touchscreens.
Any version prior to version 2.0.2 downloading to Hardware version 3
Any version prior to version 2.5.1 downloading to Hardware version 4
Any version prior to version 2.6.0 downloading to Hardware version 4.5
Fix: Install new version of EasyBuilder on your computer.
Set DIP Switch 2 ON in the HMI and reset Unit.
Load your project using new EasyBuilder.
Set DIP Switch 2 OFF and reset Unit.
Project should now operate normally.
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