Hi,
does the CR1000 have a limit regarding the number of channels in one table (or in all tables altogether)? E.g., if I produce a large number of values from each signal (e.g. 10-minutes-avg, max, min, std, post-processed avg, max, min, std), I might end up at more than 100 channels. Furthermore, if signals are imported by means of a "data stream" - additional to those which are acquired by the logger - the total number of channels might even be several hundreds. Would that exceed the calculation capacity? Would any other problems occur (e.g. failure of connection to the logger)?
Thanks
The number of tables that can be defined is limited to 30. The number of data values that can be stored in the tables is based on other factors in the program.
The total SRAM (2M or 4M) is shared by: some functions of the operating system, operating system settings such as those that are found in the Settings table (PakBus address, Station Name, PakBus settings, etc), the compiled program, and memory needed for communications. If a USR drive is specified that is allocated. The remaining is used for Public variables, followed by data tables. For data tables, fixed tables are allocated first and then remaining memory is divided among the auto allocated tables, with an attempt to be made that all auto allocated tables are filled at about the same time.
Any limit you run into will be based upon these factors, so it will vary from program to program. To optimize your program, there are things you can do, such as declaring arrays where possible and then aliasing if necessary (rather than declaring separate variables simply because you want a unique name), and declaring variables as Dim where possible rather than Public. Note that each variable requires about 250 bytes of memory.
Dana W.
You indicate that variable set up as Dim takes less space than one declared Public. What is the storage requirement for each? I just scanned my CR5000 manual and don't see anything related to it.
The datalogger allocates space in a memory buffer for values that are Public, in order to display them. There are also buffers for certain instructions, such as GetRecord & the Tablename.Fieldname syntax, the TableFile instruction, and PakBus data collection (not relevant for the CR5000).
Section 12 of the CR1000 manual has information on datalogger memory. It doesn't look like this same information is in the CR5000 manual.
Dana W.