Tektronix DM 5010, Инструкция по эксплуатации

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DM 5010
Instrument
Interfacing
Guide
hold up bus traffic any longer; it outputs a byte with all
bits set to one (FF hex) and asserts EOI concurrently.
This does not change the value stored in the INPUT
target variable. If the variable was undefined, it re­
mains undefined. This causes an error if the variable is
numeric and it is subsequently used in an output
statement or a calculation.
Because the DM 5010 returns a very large number
(1 .E+99) to indicate an overrange condition, it is nec­
essary
to define variables used for readings in the
4041 as long floating point. Such a variable is used in
the 4041 sample measurement program.
Using DM 5010 Interrupts
Programmable interrupts are provided in the DM
5010 to inform the controller of asynchronous events,
such as operation complete, command errors,
overranging, or out-of-limits reading in the compare
mode. If the DM 5010 is set to report an event, it
asserts SRQ when it detects that event and sets its
status byte and error code appropriately. The status
byte returned in response to a serial poll and the error
code returned in response to an error query (ERR?)
correspond to the events shown in Table 3. The error
query obtains more detail in the case of abnormal
events and some normal events. For instance, in the
case of a command error, was it a problem with a
header, argument, or delimiter? You can find out from
the error code.
Here are typical SRQ handlers that alert you to a
reporting instrument's address, status, and error code
with a message on your console. The error code is
helpful during debugging because it identifies the spe­
cific command or execution problem should one oc­
cur. To use an SRQ handler, you must link it and
enable it as shown in the statements at lines 120 and
130. The sample measurement program does not use
the error query because the information that is needed
(operation complete) is available from the status byte.
It prints the status byte as a failsafe measure only if it
is other than the one expected.
4050-Series with 405XR14 Rompack:
120 ON SRO THEN
470
130 CALL "SRQON"
140 REM
150 REM
450 REM
460 STOP
465 REM SERIAL POLL OF ADDRESS 16 ONLY
470 POLL A,S;16
475 PRINT ei6:MERR?"
480 INPUT i316:E
490 PRINT "STATUS * ” »S»"ERROR-”»E
500 RETURN
4041:
120 On srq then Sosub dopoll
130 Enable sr«i
140 !
150 !
450 !
460 Stop “End of 4041 example program statements,"
470
D
opo
IH
poll stabs t ? ad dr /16.
480 Input #addr prompt "ERR?”:errnum
490 Print "STATUS="/stabat/"ADDRESS="J addr
r
"ERR0R=
"J
er rnurn
500 Resume
7