If an IQAN-MD4 that has been running SW version 4.07 or later is downgraded to any of the versions 4.04, 4.05 or 4.06, there will be problems with the touch interface.
The symptom can be seen as a delayed response of the touch buttons.
The problem is caused by a bug in versions 4.04, 4.05 and 4.06 that prevents the MD4 from replacing a configuration file that has to match the SW version in order for the touch interface to function properly. This is no issue if the module contained 4.03 or earlier before upgrading to 4.04, 4.05 or 4.06, as the earlier versions uses the same config as 4.04, 4.05 and 4.06.
If one introduces the problem by downgrading to 4.04, 4.05 or 4.06, the problem can be solved by switching to an earlier or later version that does not have the bug. The symptoms will however remain until the module is restarted by switching power off an back on.
Users of versions 4.04, 4.05 and 4.06 will be exposed to this issue, as the IQAN-MD4:s are shipped out with version 4.07 since the following serial numbers:
MD4-10, SN 1717280001
MD4-5/7, SN 1718280001
Use version 4.07 or later.
After updating, the MD4 has to be manually restarted once for the change to take effect.
Alternative workaround for using 4.04, 4.05 or 4.06
Downgrade to version 4.02, this will write the correct configuration, then upgrade to 4.04, 4.05 or 4.06
Additional note on the usage of VDIN
As stated in the IQANdesign user manual, the VDIN channel should not be used for any critical functions. Also with a properly functioning interface, there can still be delays in high-utilization application, as the soft-key (MD3) and touch button (MD4) inputs are handled by the graphics software, that does not have the same real-time performance as the machine controlling channels.
Customer support service by UserEcho