HP 3438A - HP-IB System Applications

Model 3438A
Section I11
3-24. Resistance Measurements (Front or Rear
lnput Terminals).
3-25. Procedure:
a. Depress kn (kilohms).
b. Depress proper
manuaI range or Auto for
automatic range selection (20 to 20
Mn).
c. Connect test leads from the Multimeter V ni(=) and
COM
(-) terminals to the resistance under test as shown
in Figure 3-8.
NOTE
When making resistance measurements using
the lower ohms ranges, consideration should
begiven to the resistance of the test leads. This
potential measurement error can be elimi-
nated by measuring the lead resistance and
subtracting it from the combined resistance
value of the test leads and the resistance under
test.
\
INPUT
A
ZA FUSE
1
Figure 3-8. Resistance Measurement.
3-26.
HP-16 APPLICATIONS.
3-27. Examples of typical HP-IB System operations
using the
3438A Multimeter are given to aid the user in
setting up his own system. There are two usable HP-IB
modes of operation:
a. Talk Only.
b. Addressed To Talk.
Both modes will be discussed in the following
paragraphs.
3-28. Data Output Format.
3-29. The Data Output Format and Function Codes are
shown in Figure 3-9.
- -
+DDDD EI-D
1
F C R LF
-N- -7 -
- - -
D~splay Exponent Del~rn~ter Funct~on Carnage L~ne
-2 Code Return Feed
lnput
Value
ACI
OHMS
Figure 3-9. Data Output Format and Function
Codes.
3-30. The Data Output Format is a fixed length of 13
characters. The Display and Exponent portion combine
to relate the actual input value.
Example:
If the Multimeter display reading was
+ 17.90 V in the
dcV function, the output format would be:
+ 1.790 E + I, I
\Function Code
Input Value
NOTE
There is no leading zero suppression.
3-31. Overload Indication. The output format for an
Overload Indication is:
I.DDD E + 9, F, CR, LF.
\Ek/
Overload Indication
The leading
1 and the + 9 exponent signifies an overload
indication.
3-32. Talk Only Mode.
3-33. The Talk Only Mode is used in an HP-IB system
without a controller. The Address Switches AS6 and
AS7, which are located on the A3 Logic board (remove
top cover), must be set as shown in Figure 3-10 for this
mode.
AS1 through AS5 may be set in any position.