Types Of Output Data; Numeric Data And Error Messages; Measurement Data; Numeric Output Data Format - Fluke 8842A Instruction Manual

Because the 8842A gives priority to input processing, it completely processes all
characters in the input buffer before it loads the output buffer. When the output buffer is
loaded, the Data Available bit in the serial poll register is set true.
Data from the output buffer is not actually loaded onto the IEEE-488 bus until the
controller addresses the 8842A as a talker. This is done by sending the interface message
MTA (My Talk Address).

3-42. Types of Output Data

The types of data that can be loaded into the output buffer are shown in Figure 3-6. Each
type has its own format. Error messages, which are loaded into the output buffer if an
error occurs, are formatted as numeric data.

3-43. Numeric Data and Error Messages

Numeric data is loaded into the output buffer in response to the G2 command or an
instrument trigger, and has the format shown in Table 3-2. The exponent is always a
multiple of 3, as in engineering notation. The position of the decimal point matches the
front panel display.
Numeric data is of constant length, It is 11 characters (plus terminators) when the suffix
is disabled, and 16 characters (plus terminators) when the suffix is enabled.
The suffix is enabled by the Y1 command, and consists of five ASCII characters as
shown in Figure 3-6. The suffix is appended only to numeric data, never to status data.
The terminators are determined by the Terminator commands. The default is CR LF EOI.
There are three types of numeric data: measurement data, overrange indication, and error
messages.

3-44. MEASUREMENT DATA

Measurement data has the numeric data format shown in Table 3-2, and is always in the
units of volts, amps, or ohms.
RANGE
VDC, VAC
R8 ±1x.xxxxE-3*
R1 ±1xx.xxxE-3
R2 ±1.xxxxxE+0
R3 ±1x.xxxxE+0
R4 ±1xx.xxxE+0
R5 ±1xxx.xxE+0
R6 --
* VDC only
** 4-wire ohms
*** mA DC only
Table 3-2. Numeric Output Data Format

MEASUREMENT DATA

2-, 4-WIRE k MA DC, mA AC
±1x.xxxxE+0**
±1xx.xxxE+0
±1.xxxxxE+3
±1x.xxxxE+3
±1xx.xxxE+3
±1xxx.xxE+3
±1x.xxxxE+6
OVERRANGE
INDICATION
-- ±9.99999E+9
-- ±9.99999E+9
-- ±9.99999E+9
-- ±9.99999E+9
±1xx.xxxE-3*** ±9.99999E+9
±1xxx.xxE-3 ±9.99999E+9
-- ±9.99999E+9
Remote Programming
OUTPUT DATA
ERROR
MESSAGES
+1.00xxE+21
+1.00xxE+21
+1.00xxE+21
+1.00xxE+21
+1.00xxE+21
+1.00xxE+21
+1.00xxE+21
3
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