Campbell Scientific CSM1 Card Storage Module - Manual (Page 24)

Appendix B. Internal Data Formats and Pointers in the Card Memory
B-2
The storage reference pointer (R): this points to the location where the CSM1
will write the next data value in the card.
The display location pointer (L): this points to the location that will be the first
value output in response to the C, F or HF commands. If this pointer points to a
filemark or start of a program, no data is output by these commands. You must
move the pointer past the filemark to get further data. The simplest way of
doing this is to use the NFM command. (Appendix D.)
The dump pointer (D): this is used by the PC software to recall the point from
where new data should be collected. The dump pointer points to the first
location where new data should be collected. It is up to the PC software to
move the dump pointer after successful data collection. The CSM1 does not
move this pointer.