GE PACSystems RX7i, User Manual

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Chapter 5. Ethernet Global Data
GFK-2224Q January 2017 89
Run Mode Store of EGD
Caution
Modifying an exchange using an RMS can cause an interruption in the transfer
of EGD data or possibly take the exchange offline. This is particularly a concern
for exchanges used with remote IO, such as exchanges between the CPU and
NIU. Do not use this feature unless you are sure you understand the possible
results.
PACSystems versions 5.5 and later allow you to modify EGD exchanges in a running controller without first
transitioning to stop mode. Each exchange can be configured individually to allow or disallow changing or
deleting the exchange in run mode. You can add exchanges in run mode without changing any configuration
settings.
Added exchanges begin consumption/production shortly after the activation of any logic that is part of the run
mode store sequence.
Deleted exchanges cease consumption/production shortly before the activation of any logic that is part of the
run mode store.
Modified exchanges will be offline for a short time during the activation of new logic that is part of the RMS.
This amount of time depends on factors, such as sweep mode and sweep time. All variables associated with a
modified exchange will hold their last state during the pause in consumption. The consumption timeout is
restarted for each modified consumed exchange.
The effect a run mode store has on PLC sweep times depends on communication window configuration and
the magnitude of the changes in the run mode store. Depending on the application’s configuration, modifying
exchanges in a producer with increased sweep times may cause consumption timeouts on exchanges that are
modified in applications with very low tolerances.
If the modification creates an incompatibility between the producer and consumer, the exchange will cease to
be consumed.
Any modification to an exchange’s parameters resets the
stat g
station manager data for that exchange.
Modifying an Exchange’s Parameters
The parameters that define the exchange can be modified in a run mode store. Changing some parameters
such as Exchange ID essentially redefines the exchange. This is the equivalent of deleting an existing exchange
and adding a new exchange in a single run mode store. These changes affect signature compatibility with the
associated producer or consumer(s). Changing other parameters simply alter the operation of an existing
exchange and do not affect compatibility.
For details on the use of signatures to determine compatibility, refer to “Using Signatures in Ethernet Global
Data” in Chapter 5.
Common EGD Parameters
Parameters that are shared among all exchanges cannot be modified during an RMS. These parameters are
properties of the Ethernet Global Data folder in the target.
Parameter Behavior
Local Producer ID This setting cannot be changed in a run mode store.
Use Signatures (only available when
Configuration Server is used)
This setting cannot be changed in a run mode store.
Secondary Produced Exchange Offset (Redundancy systems only.) This setting cannot be changed in a run
mode store.
Redundancy Role (Redundancy systems only.) This setting cannot be changed in a run
mode store.