HP Car 3490A manual Ldav, F D

Model3490A	Section
	III

M R E

Data Lines

		Programdata
		from controller
LDAV
	lndicates to 34904
	that data is available
H R F D
349OA will	349OAis busy and	34904 will	3490A
accept data	will not acceptdata	aocept new	busy
		data

349OAhasaccepted	3490A finished
and is processing	processing data
data

Figure3-8. Timing Diagram,3490AAddressedto Listen.

not output the reading.A new readingis initiated by reprogrammingthe 34904 or by going to local control.

3-118. M3, AddressedSinglewith Output. The instru- ment takesone readingwhen triggered and outputsthe readingif addressedto talk. If not addressedto talk, it waits for its talk addres to output or its listen addres to be reprogrammed. After output of the reading data, a new readingis initiated by reprogrammingthe 34904 or by going to local control. If reprogramming occurs before output of the reading daIa,a new readingwill be taken accordingto the new programmingdata.

3-119. M4, lnterrupt Multiple with No Output. Pro- gramming of No Output overrides that of Interrupt, so this mode is the sameasM0.

3-120. M5. InterruptMultiplewith Output. This mode is the same as Ml except that if the 3490A is not addressedto talk, it will pull the ServiceRequest(SRQ) line LOW after each reading is taken. This line is taken HIGH when the reading is outputted or when new progamming datais received.SeeParagraph3-l 16.

3-121. M6, InterruptSinglewith No Output. Program- ming of No Output overrides that of Interrupt, so this modeis the sameasM2_

3-122.MT,lnterrupt Singlewith Output. This mode is the same as M3 except that if the 3490A is not add;essedto talk, it will pull the ServiceRequest(SRQ) line LOW after eachreadingis taken. This line is taken HIGH after output of the reading data or when new programmingdatais received.SeeParagraph3-l 18.

3-123. Repeatingan Output. The 3490A can be made

to output the samereadingmore than once.This can be accomplishedby programmingthe 3490A with "M3E"

and outputting the reading.Then reprogramthe 3490A with "T3E". The 3490A canoutput the samereadingas

many times as desired.Programmingwith "TlE" initi- atesa new reading.

3-124. Addressed to Talk. The 3490A may be ad- dressedto talk by setting MRE LOW and transmitting the 34904 talk address.It may be unaddressedto talk

.-by addressingany other unit to talk, or by sendingthe character- . Figure 3-9 is a timing diagramfor data and handshak'elines when a printer is addressedto listen and the 3490A is addressedto talk.

3-125. Output Control. Two generalmodesof output are possible, depending on the remote programming of the 3490A. If normal output (AddressedMultiple or AddressedSingle,Table 3-7) is programmed,the 3490A will inhibit triggers after eachreadingand output data if alreadyaddressedto talk. Ifnot addressedto talk, it will wait for its talk addressbefore outputting data, or for its listen addressto be reprogrammedIf. Interrupt output is programmedand the 34904 is not addressedto talk, it will issuea ServiceRequest after eachreadingand await recogrition by the controller.If it is addressedto talk, it will inhibit triggers after each reading and proceed to output data.

3-126. Output Format. After the 3490A has been properly put into an ontput mode, the data will be

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