Red Lion GEMINI 2 - Manual (Page 8)

OPERATOR ACCESSIBLE FUNCTIONS WITH
PROGRAMMING DISABLED
(For details on keyboard entry, see preceding section)
One of the important features of the Gemini is the ability to disable
programming. With this ability, accidental bumping of the keys or tampering by
unauthorized personnel can be prevented. However, it may be necessary to allow
reset and certain programming functions, such as, preset and scale factor values
to be changed in daily operation. The Gemini, through the use of the “Operator
Accessible Functions” Modes, can enable these functions even when the “PGM.
DIS.” terminal is connected to “COMMON”.
The “Operator Accessible Functions” Modes are programmed by a two-digit
function code (66), like the other function modes. But in this case, the modes do
not take effect until the “PGM. DIS.” terminal is connected to “COMMON”.
(Bear in mind that all function modes of the Gemini are accessible until “PGM.
DIS.” is connected to “COMMON”.)
There are four basic “Operator Accessible Functions” Modes available.
These modes enable the following functions.
1. NO FUNCTIONS EXCEPT RESET ENABLED - In this mode, manual
reset is enabled, but none of the programming functions can be changed.
However, the functions can be interrogated.
2. PRESET PROGRAMMING AND RESET ENABLED - The entire front
panel is disabled with the exceptions of preset programmability and
manual reset. All functions can be interrogated.
3. SCALE FACTOR PROGRAMMING AND RESET ENABLED - The
entire front panel is disabled with the exceptions of scale factor
programmability and manual reset. All functions can be interrogated.
4. SCALE FACTOR AND PRESET PROGRAMMING, AND RESET
ENABLED - The entire front panel is disabled with the exceptions of scale
factor and preset programmability, and manual reset. All functions can be
interrogated.
All of these four basic modes can be modified with the addition of a minus
sign. The minus sign disables the manual reset, at the front panel and the remote
reset terminal, at the rear of the unit.
There is also a rear panel DIP switch which permits disabling of the front panel
manual reset button. This is independent of the rear terminal remote reset, and can be
used in conjunction with any front panel disable mode. The combination of manual
and remote inputs provides a high level of security without sacrificing flexibility.
DIAGNOSTICS, SELF TEST, & “WATCHDOG” TIMER
The security and integrity of the Gemini is further enhanced by its self-test,
diagnostic and “watchdog” timer capabilities.
The diagnostics are concerned with the special, no power memory of the
Gemini. Whenever the power is turned off, on purpose or by accident, all pertinent
function settings and measurements are automatically saved. Then, when power is
restored, the function and data are re-instated. This allows you to program a
Gemini once and not have to re-program it until you wish to use it in another mode.
When the function codes and data are saved, computations are made with
these values. The result of these computations is stored in the memory to serve as
a check against possible error. Then on power up, the same computations are
repeated on the stored data. If the results do not agree with the stored results, then
a “P” will appear on the left side of the display. If this occurs, refer to the
troubleshooting guide for directions.
Another error indicator is the “watchdog” timer. In order to insure proper
software functioning, the program constantly monitors itself. If the proper sequence
and timing of internal events does not occur, an “E” will appear on the left side of the
display. If this occurs, refer to the troubleshooting guide for instructions.
The final type of built-in error checking is the front panel initiated self test. It
can be performed at any time, even when the Gemini is running. It will not
interfere with the accumulation of counts or control functions. A function code of
“6” “+/-” starts the test. At this time, whatever was displayed will be replaced by
a string of decimal points and the overflow indicator. Then, the display will show
a string of 9’s, then 8’s then 7’s, etc., until a string of 0’s is shown. The self test
will then turn off the overflow indicator and activate the minus (-) sign. After this,
the unit shows an interlace pattern of -0, 1, 0, 1, 0, 1, then -2, 1, 2, 1, 2, 1, followed
by -2, 3, 2, 3, 2, 3, etc., until -8, 9, 8, 9, 8, 9, is reached. At this time, the outputs
can be tested by pressing the “1” and “2” keys.
(Theprogramdisablepinmustbehighinordertoallowactivationoftheoutput.)
Note: During self test caution should be used when testing the outputs so as not to
cause any undesirable or hazardous conditions in the system.
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