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IEEE-488 PROGRAMMING
3.9.15 Terminator (Y)
The terminator sequence that~marks the end of the instm-
merit's data string or status word can be programmed by
sending the Y command followed by an appropriate
character. The default terminator sequence is the commonly
used carriage return, line feed (CR LF) sequence (YO). The
terminator will assume this default value upon power up,
or after the inshxment receives a DCL or SDC command.
Programmable terminators include:
YO=CRLF
Yl=LFCR
M=CR
Y3 = LF
Y4 = No terminator
HP-85 Progr
amming Example--To reserve the default (CR
LF) terminator sequence, type the following lines into the
computer.
REMOTE 707
OLITFUT 767j
r i YBX '
When the second statement is executed, the normal ter-
minator sequence will be reserved; the instrument will ter-
minate each data string or status word~with a (CR LF).
3.9.16 Status (U)
The status command allows access to information con&m-
ing various operating modes and conditions of the Model
196. Status commands include:
LJO = Send machine status word.
Ul = Send error conditions.
UZ = List Translator words.
U3 = Send a value indicating the buffer size.
U4 = Send the average reading in the data stores.
U5 = Send the lowest reading in the data store.
U6 = Send the highest readiig in the data store.
U7 = Send the present value (V).
U8 = Send input switch status (front/rear).
When the command sequence UOX is transmitted, the in-
strument will transmit the status word instead of its nor-
mal data string the next time it is addressed to talk. The
status word will be transmitted only once each time the
UO command is given. To make sure that correct status i+
transmitted, the status word should be requested as soon
as possible after the con-man d is transmitted.
The format of UO status is shown in Figure 3-8. Note that
the letters correspond to modes programmed by the respec-
tive device-dependent comman de.. The default values in the
status word are also shown in Figure 3-8. Note that all
returned values accept for those associated with the ter-
minator correspond to the programmed numeric values.
For example, if the instrument is presently in the R3 range,
the second (R) byte in the status word wiJ.l correspond to
an ASCII 3.
The Ul command allows access to Model 'I.96 error condi-
tions in a similar manner. Once the sequence UlX is sent,
the instrument will transmit the error conditions with the
format shown in Figure 3-9 the next time it is addressed
to talk in the normal manner. The error condition word will
be sent only once each time the Ul command is transmit-
ted. Note that the error condition word is a&ally a string
of ASCII characters representing binary bit positions. An
error condition is also flagged in the serial poll byte, and
the instrument can be programmed to generate an SRQ
when an enur condition OCCUIS. See paragraph 3.9.13. Note
that all bits in the error condition word and the serial poll
b e error bit~will be cleared when the word is read. In ad-
d? hon, SRQ~ op%r&ion will be restored after an error con-
ditionby reading Ul.
The various bits in the error condition word are des-
aibed as follows:
TRIG ERROR-Set when the instrument receives a trigger
while it is still processing a reading from a previous trigger.
SHORT TIME-Set when the instrument cannot run as fast
as the selected data store interval.
BIG STRING-Set
if more than a 10 character message is
sent using the display (D) command.
UNCAL-Set when EVROM memory fails the self test. In-
strument calibration is invalid.
CAL LQCKED-Set when t@ng to &irate
the instrmnent
with the calibration switch in the disable position.
CONFLICT-Set
when trying to calibrate the instrument
while it is in an improper state. (i.e. dB function).
Translator Error (TRANSERR)-Set
when any one of ten
possible Translator enors occur. Table 3-15 in pmagraph 3.10
lists and describes the Translator errors.
NO REMOTE-Set
when a progamming command is
received when REN is false.
IDDC-Set
when an illegal device-dependent command
(IDDC), such as ElX is received ("El' is illegal).
3-27
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