My 3150-MCM is configured to have no Write Data, only Read Data. Occasionally, I am seeing my data overwritten with what appears to be configuration data.

My 3150-MCM is configured to have no Write Data, only Read Data. Occasionally, I am seeing my data overwritten with what appears to be configuration data.

The Write Block Start parameter must be set to a value which does not overlap with the Read Data area. A Write Start value of 75 will generally take care of this problem.

In the sample ladder for the 3150-MCM, register N7:28 is the Write Block Start parameter.