Rack Mounting; Hp-Ib Interface Connections; Address Selection; Environmental Requirements - HP 3478A Technical Manual

3478A
feet are shaped to permit stacking with other half-
module Hewlett-Packard instruments.
2-16.

Rack Mounting

2-17. The 3478A may be rack mounted by adding rack
mounting kit Option 908. The basic hardware and
instructions for rack mounting is contained in the kit. The
kit is designed to permit the 3478A to be mounted in a
standard 19 inch rack, provided that sufficient rear sup-
port is available.
2-18.

HP-IB INTERFACE CONNECTIONS

2-19. The 3478A is compatible with the Hewlett-
Packard Interface Bus (HP-IB).
HP-IB is
implementation of IEEE Std. 488-1978,
"Standard Digital
Programmable
ANSI MC. 1.1.
2-20. The interface connection is made by an HP-IB
Interface Cable to the 24 pin HP-IB connector located at
the rear panel. A typical interconnection of an HP-IB
system is shown in Figure 2-4, in which ends of the
cables have both a male and female connector to enable
connections to other instruments and cables. As many
as 15 instruments can be connected to the same
interface bus. However, the maximum length of cable
that can effectively be used to connect a group of
instruments should not exceed 2 meters (6.56 ft.) times
the number of instruments connected, or 20 meters (65.6
ft.), whichever is less. For a pictorial view of the HP-IB
connector and its pin designation, refer to Figure 2-5.
2-21.

ADDRESS SELECTION

2-22. 3478A Address. The HP-IB "talk" and "listen"
NOTE
Hewlett-Packard's
Interface For
Instrumentation" and
Figure 2-4. Typical HP-IB System Interconnection
address of the 3478A is set by the multimeter's address
switch (located at the rear panel). The talk and listen ad-
dress is a 5-bit code which is selected to provide a
unique address for each HP-IB instrument. The 3478A
normally leaves the factory with the address switch set to
Decimal Code "23". The corresponding ASCII Code is a
listen address code of "7" and a talk code of "W". Refer
to Figure 2-5 for the factory address setting of the switch.
Refer to the Remote Operation Chapter in Sec- tion III of
this manual, for more information on ad- dressing and
address codes.
2-23. 3478A Talk-Only Mode. The 3478A has a Talk-
Only Mode which is selected by the Address Switch. The
mode is selected by setting all the address switches
(switch 4 to 8) up (on). Refer to the Remote Operation
Chapter in Section III of this manual for more
information.
2-24. ENVIRONMENTAL REOUIREMENTS
To prevent electrical fire or shock
hazards, do not expose the instrument
to rain or excessive moisture.
2-25.

Operating and Storage Temperature

2-26. To meet and maintain the specifications listed in
Table 1-1, the 3478A should be operated within + 5°C (±
9°F) of the Reference Temperature. The Reference
Temperature is the temperature in which the 3478A was
last calibrated. For example, if the last Reference
Temperature was 230C (73°F), the 3478A should main-
tain its specifications if operated within ± 5°C (± 9°F) of
that temperature. The factory temperature is from 18°C
to 280C (64°F to 82°F). The 3478A may be operated
within an ambient temperature range of 0°C to 55C (32°F
to 1310F) with less accuracy.
2-3
TM 11-6625-3071-14