Why the OD1000 measurement value is 0 on my Siemens IO-Link Master?

If you use an OD1000 on a Siemens ET200 with a Siemens IO-Link master, you will observe the following behavior:

If the OD1000 cannot provide a valid measurement value (e.g. because the measurement object is out of range), the OD1000 will send the substitute value 3276.7 mm by default instead (alternatively, this value can be customized).

However, the Siemens IO-Link master will always replace this sensors substitute value with 0 (even if the OD1000 display still shows the sensor's substitute value).

This behavior is caused by a specific flag (PDvalid flag) that is included in every process data telegram. Unfortunately, there is no setting option in the settings of the IO-Link master that ignores this flag.