Honeywell Experion PKS User Manual page 218

9 PROFIBUS I/O MODULE (PIOMB) FUNCTION BLOCK
Scenario
Loading a CM
containing the
PROFIBUS
I/O Channel
Block
Reloading a
PIOMB
Reloading a
CM
Containing the
PROFIBUS
I/O Channel
Block
Reloading the
CEE
containing the
PROFIBUS
I/O function
blocks
Checkpoint
Restore of
C300
Containing
PROFIBUS
I/O Function
Blocks
Deleting a
CEE
containing the
PIOMB
Loss of communication scenarios
The following table summarizes the various communication loss scenarios and the effect of the communication
loss on the input and output type PIOMBs.
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Prerequisites
• PIOMB is active.
• CEE is in the Run state.
• C300 and PGM are
communicating.
• CM1 is active.
• CEE is in the Run state.
• C300 and PGM are
communicating.
• PIOMB is active.
• CEE is in the Run state.
• C300 and PGM are
communicating.
• PIOMB is inactive.
• CEE is in the Idle state.
• C300 and PGM are
communicating.
During Checkpoint Save
• PIOMB was active.
• CEE was in the Run
state
• C300 and PGM were
communicating
After Checkpoint Save
• PIOMB is inactive.
• CEE was in the Idle
state
You cannot delete a CEE containing the PIOMB until all contained blocks including the PIOMB and all
Control Modules containing PROFIBUS I/O channels are deleted. When all the contained blocks are
deleted, and the communication between the PGM and PROFIBUS devices stops.
Input type PIOMB
When a CM containing the PROFIBUS I/O channel block is loaded, the
input channel values are already being imaged from the PGM to the C300
so the PIOMB holds the latest values. Output channels back initialization
values are also available on the PIOMB. None of these values are used by
the I/O Channel until the CM is activated.
You must inactivate the PIOMB to reload it. You cannot make any
changes PROFIBUS-specific changes or PDC association specific
changes to the PIOMB after it is loaded. The connection remains open and
the PIOMB behavior is same as loading of PIOMB.
You must inactivate the CM to reload it. When a CM is reloaded, its
behavior is same as loading a CM containing PROFIBUS I/O channel
blocks. However, the PIOMB will hold the last output value received from
the channel block, and this value will be held by the PROFIBUS slave
device.
When C300 and PGM are
- This scenario
communicating
is identical to deleting a
PIOMB.
• The CEE block will be
loaded but the control
strategies including the
PIOMB and the Control
Module needs to be loaded
again.
• The output to the
PROFIBUS device are set to
the unpowered state.
When C300 and PGM are
communicating
• The control strategies
including PIOMBs, Control
Modules and all Operational
Checkpoint Data will be
loaded as part of the
Checkpoint Restore.
• The output to the
PROFIBUS device are set to
the unpowered state.
Output type PIOMB
When C300 and PGM are not
- This scenario is
communicating
identical to Loss of C300 power or
RAM Retention Restart.
• The CEE block will be loaded but
the control strategies including the
PIOMB and the Control Module
needs to be loaded again.
• The output to the PROFIBUS
device will be set as defined by the
DSB for a communication loss
between the C300 and the PGM.
When C300 and PGM are not
communicating
• The control strategies including
PIOMBs, Control Modules and all
Operational Checkpoint Data will
be loaded as part of the Checkpoint
Restore.
• The output to the PROFIBUS
device will be set as defined by the
DSB for a communication loss
between the C300 and the PGM.