aci eRCM Express, Руководство пользователя

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mCore Firmware Ver 01.10 Ver 2019-Oct-29 Page 84 of 97
Most PLCs will provide a Manual Control Mode for controls. This mode is often critical
when the unit is unhealthy, and needs locked in to a certain load step, when an analyst is
collecting data and unit needs to hold load step and speed during tests, and when an
operator needs to set the unit to a specific load step for review.
Nevertheless, even in Manual Control Mode, the eRCM Express should be consulted for
unit safety. Operators should not be allowed to load/unload to any unsafe load steps. Also,
if the current load step becomes unsafe, then the control panel must change to a safe load
step (even in Manual Control Mode) or Shut Down.
If the Load Step Selection Mode is not the simple
Load via Load Step Sequence method,
then some safe load steps may potentially be skipped over. This is ideal for normal
operations as inefficient or inappropriate load steps should normally be skipped over.
However, this can be problematic if the operator’s/analyst’s goal is to set the unit on one
of the load steps that is being skipped.
Thus, when the unit is put in Manual Control Mode, it may be prudent to change the Load
Step Selection from the current method to
Load via Load Step Sequence . In this mode,
eRCM Express will select NSU and NSD ( N ext S tep U p, and N ext S tep D own) strictly by
following the defined load step sequence, only skipping load steps if they are unsafe. Keep
in mind, that in this mode, the NSU can actually lead to “lower load”. However, this method
will generally allow the operator/analyst to achieve the load step they desire.
Upon leaving Manual Control Mode, reset the Load Step Selection Mode back
to the original method of the unit – simply write a zero (0) to the Load Step
Selection register. Otherwise, future data will not be appropriate for controls.
Overview:
•
User opts to enter Manual Control Mode:
o
Write a “21” to LoadStepSelectionMode
(ACI_Inputs[52]; Reg#40105)
to tell
eRCM Express that subsequent NSU and NSD values to be chosen via that
method.
▪
Method 21 is the generic Follow Load Step Sequence method, and as
such, NSU/NSD will tend to follow the defined load step sequence in
order, only skipping load steps due to safety issues.
▪
This method is the one most likely to allow an operator/analyst to load
to a particular load step and then stop it there for review/testing.
•
User exits Manual Control Mode:
o
Write a “0” to LoadStepSelectionMode to tell eRCM Express to return to its
original method for determining NSU and NSD values.