Accessing Niu Data; Accessing Module Data - GE VersaPoint IC220PBI002 User Manual

Accessing NIU Data

When accessing the NIU, use DP/V1 format.

Accessing Module Data

The PCP data from VersaPoint I/O modules is usually addressed via 16-bit object
indices. DP/V1 only has fields for 8-bit indices. More parameters have been added
to the data block for use when accessing the module data in the I/O Station.
When communicating with objects on I/O Station modules, the response should
be fetched using Read. Otherwise on the next communication attempt, the DP/V1
error code DF 80 B5 00 will indicate that the module is busy. The module is
waiting because it has not yet had a response from the last communication.
Communication is carried out via DP/V1 Index Numbers 47 (PCP Data with Invoke
ID) and 48 (PCP Data). The Object Index and assigned subindex of the I/O
module are transmitted as part of the data field.
GFK-1911B Chapter 8 Communications
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