SECTION 4. EXTERNAL STORAGE PERIPHERALS

 

 

 

 

 

TABLE 4.2-1. *8 Mode Entries

 

Display

Description

Key

ID:DATA

*8

08:00

Key 1 or 2 for Storage Area. (This window is skipped if no memory has

 

 

been allocated to Final Storage Area 2.)

A

01:XX

Key in Output Device Option. See Table 4.1-1.

A

02:XXXXX

Start of dump location. Initially the TPTR, SPTR or PPTR location; a

 

 

different location may be entered if desired.

A

03:XXXXX

End of dump location. Initially the DSP location; a different location

 

 

may be keyed in if desired.

A

04:00

Ready to dump. To initiate dump, key any number, then A. While

 

 

dumping, "04" will be displayed in the ID field and the location number

 

 

in the Data field. The location number will stop incrementing when the

 

 

dump is complete. (Any key aborts transmission after completion of

 

 

the current data block.)

4.2MANUALLY INITIATED DATA OUTPUT - *8 MODE

Data transfer to a peripheral device can be manually initiated in the *8 Mode. This process requires that the user have access to the CR10 through a terminal or the Campbell Scientific Keyboard/Display. The *8 Mode allows the user to retrieve a specific block of data, on demand, regardless of whether or not the CR10 is programmed for on-line data output.

If external storage peripherals (cassette, Storage Module, etc.) are not left on-line, the maximum time between site visitations and data retrieval must be calculated to ensure that data placed in Final Storage are not lost due to write-over. In order to make this calculation, users must determine: (1) how large their Final Storage is, (2) how many Output Arrays are being generated, (3) how many low and/or high resolution data points are included per Output Array, and (4) the rate at which Output Arrays are placed into Final Storage. When calculating the number of data points per Output Array, remember to add 1 overhead data point (2 bytes) per array for the Output Array ID.

For example, assume that 29900 locations are assigned to Final Storage (*A Mode), and that 1 Output Array, containing the Array ID (1 memory location), 9 low resolution data points (9 memory locations) and 5 high resolution data points (10 memory locations), is stored each hour. In addition, an Output Array with the Array ID and 5 high resolution data points (11 memory locations) is stored daily. This is a total of 491 memory

locations per day ((20 x 24) + 11). 29900 divided by 491 = 60.90 days. Therefore, the CR10 would have to be visited every 60 days to retrieve data, because write-over would begin on the 61st day. Most likely the user would want to retrieve data more often than this to perform a general checkout of the station.

The output device codes used with the *8 Mode are the same as those used with Instruction 96 (Table 4.1-1), with the exception of "all data to tape" (09, with *8 all data between the start and stop locations is always written) and the options to transfer data from one Final Storage area to the other (80, 81). Table 4.2-1 lists the keystrokes required to initiate a *8 data dump.

4.3 CASSETTE TAPE OPTION

The Model RC35 Cassette Tape Recorder or equivalent can be left attached to the CR10 for continuous on-line data recording or it can be periodically taken to the CR10 site for the manually initiated retrieval of the data accumulated in Final Storage. The *8 Mode is used to manually initiate tape transfer.

4.3.1 CASSETTE RECORDER

The RC35 Cassette Recorder offered by Campbell Scientific is an inexpensive recorder for use with the CR10 (also compatible with the 21X and CR7 dataloggers). The record/playback function of each RC35 is tested along with a head alignment procedure prior to shipment. CR10/RC35 connections are made with the SC92A Cassette Write Only Interface or the SC93A Cassette Read/Write Interface. The CR10 controls the on/off state of

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