HP 3457A Service Manual page 51

Operation
3457A
3-42. Input Selection. When using the General h r p o s e Multiplexer, the i n s t r i ~ m e ~ ~ l must be set f o r Rear o r
Scanner inputs.
To select Rear Inputs
-
Press the TERM
/
M coni'igi~ration hcy. Use tlic ?/AUTO o r J/HOLD scroll key
t o display REAR o r SCANNER and press the ENT
/
LAST ENTRY key.
3-43. Channel Selection. O d y one input channel, either 2-wire o r +wire, plus one actuator channel c a n b e
selected a t a time. When a n input cliannel is closed, the channel previously clostcl is opened. T h e same ap-
plies
to
the actimtor channels.
To select a n input channel
-
Press the CHAN
/
N configur:ition key, enter the number of t h e channel t o
be closed and press the ENT
/
LAST ENTRY hey.
T o close o n e of the acluntor cllannels
-
Press the Blue SHIFT hey then the OFFSET COMP
/
C key. Use
the
HOLD
scroll key t o display CLOSE. Enter the number of the actuator chnnnel t o be closed (8 o r 9 )
and press the ENT
/
LAST ENTRY key.
To open all channels
-
Press the Blue SHIFT hey then the OFFSET COMP
/
C key. Use the
HOLD
scroll key t o display CRESET and press the ENT
/
LAST ENTRY key.
3-44.
Scanning.
T h e instrimlent can be set t o automatically tahc a number of readings and stose them in
memory. This makes it possible t o measure some or all of the inpul channels and recall t h e measurements
taken. T h e following is a simple procedure t o measure inputs connected t o channels 0 through 7 of t h e
H P 44491A Multiplexer,
Determine the type of measurement you wish t o make (Voltage, Resistance, Current, Frequency/Period)
and set the instrument f o r that measuren~ent as described in the previous paragraphs.
Select the Rear/Scanner input
-
Press the TERM
/
M configuration key. Use the ?/AUTO o r ./,/HOLD
scroll key t o display REAR:2 o r SCANNER2 and press the ENT
/
LAST ENTRY key.
Set the Trigger t o Hold
-
Press the Blue SHIFT key then the STORE
/
T configi~ration key. Use the
J/HOLD scroll key t o display the TRIG c o m n ~ a n d . Press the
-t
display key once t o hold the command.
Use the ?/AUTO o r
HOLD
scroll key t o display HOLD:4 and press the ENT
/
LAST ENTRY key.
Set the number of readings f o r the number of measurements t o be made (in this case
8)
-
Press the
NRDGS
/
L configuration key, enter the number 8 and press the ENT
/
LAST ENTRY key.
Set the Scan Advance t o Auto
-
Press t h e SCAN ADV
/
0 configuration key. Use the ?/AUTO o r
JIHOLD scroll key t o display AUTO:2 and press the ENT
/
LAST ENTRY hey.
Enable the Reading Memory
-
Press the CONFIG
/
P configuration key then the ENT
/
LAST ENTRY
key.
Allocate Reading Memory space (each reading requires 4 bytes of memory)
-
Press the Blue SHIFT key
then the TERM
/
M
configuration key. Use the
HOLD
scroll key t o display
MSIZE.
Enter the number
32
(8
readings times 4 bytes) and press the ENT
/
LAST ENTRY key.
Select t h e channels t o be measured
-
Press the Blue SHIFT hey then the RECALL
/
S configuration hey.
Use the ./,/HOLD scroll key t o display SLIST. Enter the n ~ ~ m b e r of each channel you wish t o measure fol-
lowed by a comma (,) t o separate them (example: 0,1,2,3,4,5,6,7). Press the ENT
/
LAST ENTRY key.
( A $
nrarty as 16 single digit charrrtel nrcrtrhers or 8 dorchle digit clrc~rtrtel rtrcrrrbers ccln be entered at orre tirne. 7'hc rruntb~r of read-
ings ( N R DGS) should Be set for the rrtcrnl~cr of charrrrels entered).