Rockwell Automation 1402-LSM Line Synchronization Module Installation Instructions - Manual (Page 44)

Chapter 4
Application Information
4–10
Data Files Used Continued
The following description applies to both files N21 and N22.
The data at word 0 of N21 and N22: 1 must be the same. N2x:0 is the reset
word for the sequencer and N2x:1 is the first word in the rotation of the
sequencer.
The data held in file N21 consists of the block transfer numbers needed to
complete configuration in the order necessary to perform that task. This data
must be as shown in the file N21 description for a sequencer size of 4. See
Data File Table 4.5. The sequencer size may be altered, but no smaller than
4. If the size is expanded, the pattern of data in file N21 MUST be extended
in the same fashion as it is shown below in the file N21 description.
The data held in file N22 consists of the block transfer numbers of the data
desired in run mode. With the sequencer size set to 8, eight different block
transfers may be executed sequentially. The numbers entered in file N22 may
be altered to change the order of “run mode” block transfers being executed.
The sample data as shown in the file N22 description ensures that the BTR
for Synchronizing Bus Error Parameters occurs at regular intervals (i.e. 3
BTRs apart) and twice as frequently as any of the other block transfers.
See Data File Table 4.5.
Note: Even though the block transfers may occur at a certain rate, the data
they are transferring may not have been updated internally by the LSM.
Changing the BT order in the sequencer may not significantly change the
update rate of “new” data.
If more or different block transfers are desired, the sequencer size can be
expanded and the files N21 and N22 MUST be expanded by the same
amount.
Important: Failure to expand the data in files N21 and N22 will result in
improper operation of the block transfer ladder, and possibly even a FAULT
of the processor due to invalid indirect offsets. See Data File table 4–5.
Ladder Program Description
Continued