Campbell Scientific CR7 Measurement and Control System - Manual (Page 54)

SECTION 4. EXTERNAL STORAGE PERIPHERALS
4-2
Only one of the options 1x, 2x, or 30 may be
used in a program. If using a SM64 Storage
Module, output code 21 should be used. Use of
the SM192/716 is discussed further in Section
4.4, print output formats are discussed in
Section 4.5.
4.1.2 *4 MODE
The *4 Mode may be used in place of
Instruction 96 to enable or disable printer output
and to set the printer baud rate. The first
parameter is a two digit number determining the
printer status. The second is the baud rate
code. To enter a different status, key in the
appropriate code from Table 4.1-2, followed by
"A". Printer data is sent in the printable
ASCII format only (Section 4.5). If printer
status is changed during execution of the
program tables, execution stops until the
programs are recompiled. Instruction 96 should
be used to send data to the SM192/716 Storage
Modules. Do not use *4 if Instruction 96 is used
in the program.
TABLE 4.1-2. *4 Mode Parameters and Codes
Keyboard Display
Entry ID: Data Description of Data
*4 04:00
A 01:XX Output Enable Code
A 02:XX Baud Rate Code
Output Enable Codes
Code Description
00 printer disabled
01 printer enabled, ASCII
Baud Rate Codes
Code Baud Rate
00 300
01 1200
02 9600
03 76,800
4.2 MANUALLY INITIATED DATA
OUTPUT - *9 MODE
Data may be transferred to tape using the *8
Mode and to printer or Storage Module using
the *9 Mode. These Modes allow the user to
retrieve a specific block of data, on demand,
regardless of whether or not the CR7 is
programmed for on-line data output.
If external storage peripherals are not left on-
line, the maximum allowable time between
visiting the site to retrieve data must be
calculated to insure that data placed in Final
Storage are not written over before they are
collected. In order to make this calculation,
users must determine: (1) the size of Final
Storage, (2) the number of output arrays being
generated, (3) the number of low and/or high
resolution data points included in each output
array, and (4) the rate at which output arrays
are stored in 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 19,296 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).
19,296 divided by 491 = 39.3 days. Therefore,
the CR7 would have to be visited every 39 days
to retrieve data, because write-over would begin
in the 40th day.
4.2.1 MANUAL STORAGE MODULE OR
PRINTER DUMP - *9 MODE
Using the *9 Mode, data in Final Storage can be
transmitted as ASCII or binary data out the
serial port by manually initiating a dump. If on-
line printing is enabled with Instruction 96 or the
*4 Mode, entering *9 will stop it. On-line printing
will be re-enabled if no keyboard entries are
made for 3.4 minutes. Return to the *0 Mode
when the dump is completed.
When on-line Storage Module or printer transfer is
not enabled and the *9 Mode is used to dump new
data, the start of dump pointer (PPTR) will remain
where it was when the dump was completed or