3478A
Table 3-4. Status Byte Definitions
Octal
Decimal
Bit
Definitions
Code
Code
001
1
0
Data Ready - Indicates to the controller
that measurement data is ready to be
output. The Require Service Message
and bit is cleared when the controller
begins to accept the data or when the
reading is no longer available.
See
paragraph 114.
002
2
1
This bit is always at 0 (0=high).
004
4
2
Syntax Error - This shows that an
invalid Program Code(s) has been sent
to the 3478A (e.g. F9).
010
8
3
Internal Error - Shows that a failure in
the 3478A is detected. This may be a
failure in the Self-Test Routine (see
paragraph 3-60), the A/D Converter, or
a checksum error in the Calibration
RAM (checked every time a reading is
taken).
More information can be
obtained by reading the 3478A’s error
register. See paragraph 3-120.
020
16
4
Front Panel SRQ - This bit is set when
the 3478A’s Front Panel SRQ button is
pressed. See paragraph 3-115.
040
32
5
Invalid Calibration - When this bit is
set, an attempt to calibrate the 3478A
has failed.
100
64
6
This is the SRQ bit. This bit is true
only if a Require Service Message is
output.
200
128
7
Power-On
SRQ
- Shows
that a
power-on reset has occurred.
See
paragraph 3-106.
Note: More than one bit in the Status Byte can be true
(see paragraph 3-87). is output (the Status Register’s
Data Ready bit is true). The only way the SRQ Message
is output is if the Front Panel SRQ condition is true.
3-87. More than one bit in the Status Byte Message can
be true.
For example, bit 0, 2, and 4 are true
(remember, bit 6 is true for any SRQ condition, if the
SRQ Mask is set for the condition) making the resultant
Status Byte look like the following:
NOTE
A "1" in this example shows a true condition.