User`s guide

20 Wonderware Siemens SIMATIC NET S7 I/O Server
The item data list box displays information about each item. The box is divided into 6
columns. The first column displays the message type and the orderid of the message
which contains this item (‚P‘ for a polled message and ‚C‘ for a cyclic message). The
second column shows the filling of the request and response PDU. The maximum value
is the PDU size shown above in the monitor window. The third column displays the
data quality. The fourth column shows the timestamp of the last update of that item.
The fifth column shows the raw item value prior to conversion in HEX. Only message
data are displayed as an ASCII string and real data in a short real format. The last
column contains the item name.
There are six basic data quality states an item can have:
Data quality good 00C0
Data communications are good. Data is good.
The register was read or written without any problems
converting the data.
Clamp hi 0056
Data communications are good. Data is not good.
The data is clamped at high limit.
The register was read or written OK but it was necessary to
clamp its value to a limit.
The value is larger than the maximum allowed.
A string is truncated.
Example: A floating point value is clamped to
FLT_MAX.
Clamp lo 0055
Data communications are good. Data is not good.
The data is clamped at low limit.
The register was read or written OK but it was necessary to
clamp its value to a limit.
The value is smaller than the minimum allowed.
Cannot convert 0040
Data communications are good. Data is not good.
The data could not be converted.
The server may return either a constant in place of the data
or return quality information alone.
The data is not useable, it is not known whether the value
is too large or too small.
Incorrect data type.
Floating point not-a-number.
Example: 0x000a in a PLC BCD register.