Address Switch And Srq Status - HP 8901B Operation And Calibration Manual

Model 8901B Operation
Operating Mode
T
Digit
L
Digit
Talk and Listen
0 0
Talk
Only
1
1 o r 0
Talk Status
Only
1-
1 or0
Listen
Only 0 1
SRQ Light: Lights when the Service Request message has been sent (SRQ line true), and the front
panel has been updated.
S Digit
1
o r 0
1
o r 0
1 o r 0
1
o r 0
Reading the HP-IB Address Switch and SRQ Status
The HP-IB switch sets the instrument address and the Talk and Listen modes of the instrument. To
display the state of the HP-IB address switch and the SRQ Line in binary, enter 21.0SP.
This display does not time out. To clear the instrument display, press the CLEAR key.
The format of the display is as follows;
AAAAA.TLS
where AAAAA is a five-bit binary address with leading zeros blanked and TLS represent the status of
the TOK switch, LON switch and SRQ bus line respectively.
NOTE
If T and L are both
1,
the instrument
is
set to Talk Only (Talk Only
overrides Listen Only
).
If all A bits are
1
and T
is
1,
the instrument will Talk Status Only
(that is, output the status byte only).
A list of possible conditions of the TLS digits of the display is provided in the following table:
Example.
If 1110.001 is the address displayed, then the HP-IB address is 1110 in binary (that is, 14
in decimal). The T digit is "0", and the L digit is
"0"
indicating that the instrument is set to be able to
Talk and Listen. The S digit is 1 indicating that the instrument is issuing a Service Request Message.
For the same example, if the BUS ADRS key is used, Addr =
14
will be displayed. (No information
about Talk Only, Listen Only, or SRQ is displayed.)
Setting the HP-IB Address.
The Modulation Analyzer's talk and listen addresses are switch selectable
as described in paragraph 2-7. Refer to Table 2-2 for a comprehensive listing of all valid HP-IB
address codes.
Updating the HP-IB Address Display.
The HP-IB address display is continuously updated. When
the switch setting is changed, the result is immediately visible on the display.
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