ProSoft Technology MVI56-104S - Manual (Page 60)

MVI56-104S ♦ ControlLogix Platform Ladder Logic
IEC 60870-5-104 Server Communication Module User Manual
Page 60 of 188
ProSoft Technology, Inc.
November 18, 2009
Block Transfer Statistics Data Object (BlkStat870)
This low-level data type creates tags to hold module status values that show
input and output image (I/O) block transfer activity. These block transfers occur
between the module and the ControlLogix processor. This low-level structure is
used to create the higher-level structure, InStat870.
Name Data Type Description
Read INT Total number of input image blocks transferred
Write INT Total number of output image blocks transferred
Parse INT Total number of blocks parsed (good blocks received and
processed)
Err INT Total number of block transfer errors (bad blocks or no
blocks received)
These tags hold values of module internal counters that keep a running total of
how many input and output image blocks have been transferred between the
module and the ControlLogix processor. During normal operation, the values
displayed for Read, Write, and Parse should increment together and be very
close to the same values, unless backplane errors are occurring. If backplane
errors are occurring, the Err value will increment and the Parse value will not.
As long as Read, Write, and Parse continue to increment and Err does not
change, this indicates normal backplane activity. An occasional backplane error
may occur, even in normally functioning systems. So, if the value in the Err
counter slowly increases over time, this is generally not a cause for concern.
However, if normal backplane transfers appear sluggish or non-functional, if input
data is being lost or output data is not being sent, especially when the Err
counter is incrementing frequently, this could indicate a hardware failure, I/O
configuration problem, or, for remote rack installations only, a process network
problem that may need to be corrected.