Rockwell Automation 284 ArmorStart User Manual - Manual (Page 277)

ArmorStart® to ArmorPoint® Connectivity 11-9
The value to be modified is the .data element of the structure. For
reference, the Min_value, Max_value, and Name_String for the
parameter is also in the structure, so that the user knows what the
minimum and maximum allowable values are for the data. It is
important to realize that the data is in a raw format. In other words,
this data could be considered a Boolean, a bit mask, an ASCII string,
an integer, a byte, etc., depending on the definition of the parameter in
the ArmorStart. Also, there could be an implied decimal point,
scaling, and different units involved.It is important that the user
fully understand and verify the raw data value being modified
with the user manual, so that it is correctly interpreted by the
ArmorStart or undesired operation in the ArmorStart may occur.
Once the data is written, during a System Wide Write function, the
ladder logic will read it back and put into the .Last_Read_Value of
the structure. This will be a handy visual verification that the data was
written correctly.
Triggering a System Wide Read
Once the system configuration has been done, a System Wide Read
must be initiated. The logic to trigger both a System Wide Read and
Write is contained in a subroutine called Handle_All_Armor. The
rungs are shown below for reference.
Figure 11.12Handle_All_Armor Rungs
To trigger the system wide read, the contact
Read_All_Condition_Here needs to be energized in the ladder logic.
This can be done through additional logic or simply by energizing the
bit, on-line, in the RSLogix5000 software, Controller Tag monitor
screen. The Read_All_Condition_Here is handled as a one shot
inside the logic, but should be de-energized at a later time. This is so a
system wide read is not triggered after every Logix power cycle or for
each transition from Program to RUN mode. When the read finishes
successfully, the Read_All_System_Done_Flag bit energizes in the
logic. However, if an error occurs during the read, the
Read_All_System_Error_Flag bit energizes and the error will be
logged into the structure called Error_Report.