Campbell Scientific CR7 Measurement and Control System - Manual (Page 34)

SECTION 1. FUNCTIONAL MODES
1-6
1 describes what the values seen in the *B
Mode represent. The correct signatures of the
CR7 PROMs are listed in Appendix B.
A signature is a number which is a function of
the data and the sequence of data in memory.
It is derived using an algorithm which assures a
99.998% probability that if either the data or its
sequence changes, the signature changes.
The signature of the program memory is used
to determine if the program tables have been
altered. During the self check on power-up, the
signature computed for a PROM is compared
with a signature stored in the PROM to
determine if a failure has occurred. The
algorithm used to calculate the signature is
described in Appendix C.
The contents of windows 8 and 9, PROM
version and version revision, are helpful in
determining what PROM is in the datalogger.
Over the years, several different PROM
versions have been released, each with
operational differences. When calling Campbell
Scientific for datalogger assistance, please
have these two numbers available.
TABLE 1.6-1. Description of *B Mode Data
Key Display
Entry ID: Data Description of Data
*B 01: XXXXX Program memory
Signature. The value is
dependent upon the
programming entered
and memory allotment. If
the Tables have not been
previously compiled, they
will be compiled and run.
A 02: XXXXX First PROM Signature
03: XXXXX Second PROM Signature
04: XXXXX Third PROM Signature
A 05: XXXXX Memory status, No. K
RAM and ROM
A 06: XXXXX No. of E08 occurrences
(Key in 88 to reset)
A 07: XXXXX No. of overrun
occurrences (Key in 88 to
reset)
A 08: X.XXXX PROM version number
A 09: XXXX. Version revision number
A 01:00 Enter I/O Module No. to
test (usually 1)
1A 01:XXXXX I/O Module 1 RAM
Signature
01:XXXXX I/O Module 1 PROM
Signature
1.7 *C MODE -- SECURITY
The *C Mode is used to secure the user's
program information. If security is activated,
then the CR7 will block keyboard access to the
*1, *2, *3, *4, and *A Modes. Activated security
will also block Telecommunications access to
the *1, *2, *3, *4, *5, and *D Modes and the
Telecommunications C command. A four digit
password allows entry to the *C Mode and
becomes part of the program memory, affecting
the program signature. If security is enabled
when *C is keyed, the password must be keyed
in before one can advance to window 1. If
security is disabled, keying *C brings up window
1 immediately. In window 1 a command can be
entered to either enter a new password (1), or
temporarily disable security (00) in order to
check or alter the programming. The password
on power-up is 0000 (unless *D was used to
create a custom PROM with the password built
in), which disables security. When security is
temporarily disabled, it is possible to enter all
modes and to alter programming. Keying *0 or
*6 will automatically re-enable security, unless
the password is 0000.
Entering the four digit password as an indexed
value (i.e. xxxx--, entered by keying C after
entering the four digits) blocks access to the *1,
*2, *3, *4, and *A Modes, but allows the user to
view and change the password.