HP 3468A - Interface Connections and Fuse Replacement

The -hp- Model 3468A is compatible with the Hewlett-Packard Interface Loop (HP-
IL). HP-IL is an easy to use interface that allows interaction and control between
the -hp- 41 family of calculators and instruments such as the 3468A. Instruments
are connected together in series, forming the ‘‘loop’’. Refer to Appendix A for
specific information regarding HP-IL.
The 3468A may be connected at any point in the loop. Refer to Figure 5-3. HP-IL
connections to the 3468A are by two cables, one going to the previous instru-
ment in the loop (IN) and the other going to the next instrument (OUT). All of the
interface cables must form a continuous loop. All connectors are designed for
proper orientation. To connect a device such as the 3468A, first turn off the
calculator and the device to be added to the loop. Then, disconnect the loop in
one place and connect the 3468A into the loop at that place. All devices must be
turned on for the interface to work properly. The calculator assigns new addresses
to each device at turn-on. Total cable length between any two consecutive
devices in the loop must not exceed 10 meters (33 feet) for standard cable.
Figure 5-3. Typ
Address Selection
“HP-IL System Interconnection
Each device in the loop is assigned a unique address - a number from 1 to 30 -
allowing the controller to specify and control individual devices. The 3468A has a
default address of 22, however, the system controller (calculator) is able to assign
new, sequential addresses to each device in the loop. These addresses start with
address 1 for the first device in the loop after the calculator in the direction of in-
formation transfer. In this way, each device has an unique address, which the
device stores internally.
f
Fu se Replacement
Amps Terminal Fuse
The Amps terminal fuse is located physically inside the Amps (A) terminal on the
multimeter front panel. To replace the fuse, first remove the cable from the Amps
terminal and then turn the power off to the multimeter. Use the side slots on the
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