Front Panel Operation
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external temperature is enabled or disabled from the TEM-
PERATURE item.
Temperature measurements can be expressed in °C, °F or K.
See DISPLAY of the GENERAL MENU to select the de-
sired reading unit.
LIMIT-CTRL: The Model 6517A incorporates an A/D hard-
ware limit circuit to detect out of range noise spikes. When
enabled (ON), the "OutOfLimit" message is displayed when
an out of range noise spike occurs. With the hardware OFF,
the error message is disabled. In the OFF state, out of range
spikes may cause erroneous readings.
TIMESTAMP
A timestamp is available for readings sent over the bus and
for readings stored in the buffer. This GENERAL menu se-
lection is used to configure the timestamp for readings sent
over the bus. From the front panel, readings are sent over the
bus via the COMMUNICATION selection of the MAIN
MENU (see paragraph 2.19.2). See paragraph 2.16.1 to con-
figure the timestamp for buffer readings.
Specifically, this selection is used to perform the following
operations:
• Select the type of timestamp; relative or real-time.
• Reset the relative timestamp to zero.
• Reset the reading number to zero.
Timestamp and the reading number are only included with
each reading if they are selected as GPIB or RS-232 data el-
ements (see paragraph 2.19.3).
The menu items for TIMESTAMP are explained as follows:
TYPE: This item is used to check or change timestamp type.
Note that changing the timestamp type clears the buffer. The
two timestamp types are described as follows:
• RELATIVE TIME — With this selection, timestamps
are oriented to a timer and reference each reading to a
point in time. The timer starts at 0.000000 seconds
when the instrument is turned on or when the relative
timestamp is reset (see RESET-TIME). After
99,999.999999 seconds, the timer resets to zero seconds
and starts over.
• REAL-TIME — With this selection, timestamps are
oriented to the real-time clock and provide the current
time (24-hour format) and date for each reading.
Timestamp type for bus readings is coupled to timestamp
type for buffer readings. Thus, if you change timestamp type
from this menu structure, it also changes in the CONFIG
DATA STORE menu structure (see paragraph 2.16.1).
RESET-TIME: This item is used to reset the relative time-
stamp to 0.000000 seconds. The timestamp also resets to
zero seconds when the instrument is turned on. It has no ef-
fect on the real-time clock.
RESET-RDG#: This menu item is used to reset the reading
number to zero. The reading number also resets to zero when
the instrument is turned on.
DISPLAY
This menu item is used to select the exponent mode (engi-
neering units or scientific notation) for display readings, and
lets you specify displayed decimal points as either periods or
commas:
NUMERIC-FORMAT: This item is used to select the expo-
nent mode:
• ENGR — Use this option to display readings using en-
gineering units (i.e., 1.00000µA).
• SCIENTIFIC — Use this option to display readings us-
ing scientific notation (i.e., 1.00000e-06 A). The two
following options are available for the scientific nota-
tion exponent mode:
FLOATING: With this selection, the exponent value
will change automatically to provide optimum reading
resolution.
FIXED: With this selection, the exponent value will re-
main fixed. Only the mantissa part of the reading will
change. After selecting FIXED, the currently selected
exponent value will be displayed. If you change the ex-
ponent value, be sure to press ENTER.
DECIMAL-CHAR: This item is used to select between peri-
ods and commas to signify decimal points on the front panel
display:
• PERIOD — This option selects the period (.) as the dec-
imal point for readings.
• COMMA — This option selects the comma (,) as the
decimal point for readings.
TEMP-UNITS: Use this menu item to select the units (°C, K
or °F) for internal or external temperature measurements.
CLOCK
The Model 6517A has a real-time clock that is used for time-
stamping bus and buffer readings (real-time timestamp), and
as a control source for the Arm Layer (Arm Layer 1). This
