HP 4262A User Manual

Section VIII
Paragraphs 8-37 to8-39
8-37. OPTIONS.
8-38. The theory of operation for the 4262A
optional circuits is outlined in the following para-
graphs. The currently available options (001, 004
and 101) with a summary of their functions and
the material fumished are listed in Table 8-1.
Figure 8-9 is a block diagram showing the option
section when all available optional equipment is in-
stalled. The basic instrument and the individual
option sections are interconnected by 8 bit data
bus lines through which both measured and control
data are transferred.
8-39. OPTION 001 BCD DATA OUTPUT (A35).
Option 001 BCD OUTPUT CONTROL (A35) con-
sists of a Data Bus Driver/Receiver and two shift
Register Files which momentarily store the meas-
ured data for simultaneous transfer of the com-
plete data to BCD DATA OUTPUT connectors.
Timing control of the A35 circuitry is done by
nanoprocessor Device Select signals DSR11,
DSW13, DSW14 and DSW15. When 4262A TRIG-
GER function is set to EXT, the instrument can be
triggerred by an EXE (extemal encode) signal in-
putted from either BCD DATA OUTPUT connec-
tor J7 or J8 (pin 46). After a measurement cycle
ends, a DSR11 pulse signal sets Data Bus Driver/
Receiver U10 to driver mode. As long as the
DSR11 signal is valid, the switch setting of the
SER/PRL switch (A35S1) has access to the nano-
processor for assigning the output data format in
parallel (simultaneous) or serial (altemate) se-
quences. The data output timing for both simul-
taneous and alternate sequencing is diagrammed on
Page 8-70. To simplify the explanation, only the
parallel output sequence is discussed here. The
measured data is stored in the shift registers in syn-
Model 4262A
chronism with DSW13 and DSW14 pulses (each
outputted 8 times during the data transfer cycle).
The Data Bus Driver/Receiver is set to receiver
mode to allow the measured data to pass through
the device. First, a DSW13 pulse train causes the
shift registers U9, Ul1l, U12 and U13 to store the
LCR data which is simultaneously transferred with
the pulse train. Successively, a DSW14 pulse train
actuates shift registers U4, U5, U6 and U7 to store
the sequentially transferred DQ data. One shot
multivibrators U1A/B generate an output pulse
train consisting of pulses that are somewhat shorter
than the input DSW pulses. This eliminates the
possibility of the shift register not storing the input
data because of a DSW signal timing error. One
transfer data group is stored in the first 1/8 stack
of each shift register when {riggered by the rising
edge of the one shot multivibrator output pulse.
Thus, a total of 16DSW pulses complete storage
of all data in the shift register file during the data
transfer phase. Next, a DSW15 pulse activates the
“two times” Flip Flop U2 — one delayed for 1.2
msec after the other. Thus, the Flip Flop generates
FLAG pulse which commands the extemal record-
er to print the measured data concurrently pre-
sented at the LCR and DQ BCD output connec-
tors. After the FLAG signal is transferred, a peri-
odic DSR11 pulse actuates the Data Bus Driver/
Receiver and frequently sets it to driver mode to
monitor the status of the INHIBIT signai output-
ted by the extemal recorder. The DSR11 pulse
train continues until the nanoprocessor senses a
change in the logic of the INHIBIT signal (meaning
that printing is complete). In alternate data output
format, the data storage and output cycle for LCR
precedes that for DQ. Hence, Device Select signals
are alternately provided for both an LCR and a DQ
output cycle[as shown in Timing Diagram(Page 8-70)).
Table 8-1. Currently Available Options.
OPTION FUNCTION MATERIAL
Provid i
orroo [P meenaionmaDadsa s |\ oo oureur cowrao
BCD DATA OUTPUT e ’ (04262-66535)
status in BCD code at rear panel connectors.
A24
Bt_xilt—in comparator compares measured value OOMPARAT(O(EZC;;N_G?Q&I;
OPT. 004 pith LOR and DQ HIGH and LOW limits, =~ 44 THUMBWHEEL SWITCH
ata in display and by Relay
COMPARATOR and TTL output (04262-66504)
: A5 COMPARATOR KEYBOARD]
(04262-66505)
OPT. 101 Provides system interface capabilities in accord- A25 HP-IB IN;rofigg?_ggsza
HP-IB COMPATIBLE | 2nc¢ With [EEE-STD-488-1975 recommenda- A3 HP-IB CONNECTOR
(04262-66503)
8-14

HP 4262A Specifications

General

Brand	HP
Model	4262A
Category	Measuring Instruments
Language	English