If the PCD2/3.W220Z18 card is plugged in to a ‘Power PCD‘ and if all 8 analog inputs channels of the PCD2/3.W220Z18 module are connected to 8 PT100 sensors then the measured PT100 temperature values of the 8 channels are not correct.

‘Power PCD’s’ are:

• PCD1.M2x20, PCD1.M2160, PCD1.M2220-C15
• PCD2.M5540, PCD2.M5440, PCD2.M4160, PCD2.M4560
• PCD3.Mxx60

To solve the issue, use and connect only up to 7 PT100 sensors to the PCD2/3.W220Z18 or do use a PCD2/3.W350 module, if all 8 PT100 are needed.

On the ‘old’ PCD’s like PCD2.M170 or PCD3.M5540 the PCD internal power supply V+ was at 24V

On the ‘new’ ‘Power-PCD’s’ the V+ is 16,5V

The electrical design of the PCD2/3.W220Z18 was done in that the way, that the internal power V+ of 24V was required to handle all 8 PT100 channels.

Since the ‘Power PCD’s’ have a V+ of 16,5V the driver on the PCD2/3.W220Z18 don’t have enough power to handle all 8 PT100 signals correctly.

To solve the issue, use and connect only up to 7 PT100 sensors to the PCD2/3.W220Z18 or do use a PCD2/3.W350 module, if all 8 PT100 are needed.

Depending of the hardware version of the W6x5 module and the I/O slot where the W6x5 module is plugged in, it’s possible that the analog output signal supplied from the W6x5 is not stable and is oscillating.

Symptom
The outputs of the PCD2/3.W6x5 do not deliver stable signals when placed on I/O slot 15 if hardware version B of the W6x5 is used.
If FBoxes are used for writing to the outputs, the FBox indicates temporarily an error.

Reason
The W6x5 modules with hardware version B are not correctly handling the Watchdog output (O 255).
Note that this is only the case if the module is placed on I/O slot 15 (base address 240). On all other slots the modules work correctly.

Solution
This problem is solved with hardware version A or C and newer of the PCD2.W6x5 or PCD3.W6x5 respectively.