HP 3478A Technical Manual page 28

3478A 3478A
3-76. 3-76. Data. Data. The Data Message The Data
information between the 3478A and the controller. information between the 3478A and
a. a. The message is used The message
multimeter and consists primarily of set-up information multimeter and consists primarily of set-up information
(e.g. (e.g. DC DC Volts, Volts, 30V 30V Range, Range, etc.).
Listener and the controller is the Talker. Listener and the controller is the Talker.
b. b. The message The message is also is also used by
receive data receive data from from the the 3478A.
multimeter's output (readings) and status information. In multimeter's output (readings) and status information. In
this case, the 3478A is the Talker and the controller is this case, the 3478A is the Talker and the controller is
the Listener. the Listener.
3-77. 3-77. Trigger Trigger (GET, (GET, Group
Trigger message causes the 3478A to initiate a Trigger message causes the 3478A to initiate a
measurement cycle. It is an measurement cycle. It is an HP-IB Trigger and
the multimeter in any trigger mode, since it has priority the multimeter in any trigger mode, since it has priority
over the over the other trigger other trigger modes. modes. If the 3478A
during a measurement cycle, the cycle is aborted and a during a measurement cycle, the cycle is aborted and a
new cycle is initiated. new cycle is initiated. There may be
sec) if a cycle is in progress when the trigger is received. sec) if a cycle is in progress when the trigger is received.
The multimeter has to be programmed to "listen" to The multimeter has to be programmed to "listen" to
execute the trigger. execute the trigger.
3-78. 3-78. Clear (DCL Clear (DCL or SDC: or SDC: Device Clear or
Device Clear). A Clear places the 3478A Device Clear). A Clear places the 3478A into its turn-on
routine (see paragraph 3-7 routine (see paragraph 3-7). ). In addit
address switch (see paragraph 3-92) address switch (see paragraph 3-92) is read and the
SRQ Mask is set to zero or octal 200 (if the Power-On SRQ Mask is set to zero or octal 200 (if the Power-On
SRQ switch is on, se SRQ switch is on, see paragraph 3-106 e paragraph 3-106). ). If If during
turn-on routine an error is detected, the hardware error turn-on routine an error is detected, the hardware error
bit in the serial poll bit in the serial poll register is set. register is set.
3-79. Remote. The Remote 3-79. Remote. The Remote Message allow
to be to be controlled ov controlled over the er the HP-IB.
panel buttons, except the LOCAL and Front Panel SRQ panel buttons, except the LOCAL and Front Panel SRQ
buttons, are disabled. buttons, are disabled. The Local and
buttons are only disabled when the 3478A is in remote buttons are only disabled when the 3478A is in remote
and local lockout (see paragraph 3-81) and local lockout (see paragraph 3-81). . The
state in remote is determined by the local state before state in remote is determined by the local state before
being placed in remote. being placed in remote. The RMT annu
display will also be display will also be on with the 3478A in remote. on with the 3478A in remote.
3-80. Local. 3-80. Local. This message clears the remote operation This message clears the remote operation
of the 3478A and enables its front panel operation. of the 3478A and enables its front panel operation.
Pressing the front panel LOCAL button also places the Pressing the front panel LOCAL button also places the
multimeter in the local state (if the button has not been multimeter in the local state (if the button has not been
disabled by the Local Lockout Message, see next disabled by the Local Lockout Message, see next
Message is used is used to t to transfer
the controller.
is used to to send da send data t ta to th
etc.). The The 3478A 3478A is is the
used by the cont the controller to
3478A. This This includes includes the
Group Execute Execute Trigger). Trigger).
HP-IB Trigger and triggers
If the 3478A is triggered is triggered
There may be a delay a delay (up to .5
Device Clear or Selective
into its turn-on
In addition, the ion, the multimeter's multimeter's
is read and the
during the
Message allows the 34 s the 3478A
HP-IB. In remote, In remote, the front
The Local and Front Panel S Front Panel SRQ
The instrument instrument
The RMT annunciator on nciator on the
ransfer paragraph). paragraph).
3-81. . Local Lockout.
3-81
o the e disabled with this message, if the 3478A is in remote. disabled with this message, if the 3478A is in remote.
The message is in effect until cleared over the HP-IB or The message is in effect until cleared over the HP-IB or
the power is cycled. power is cycled.
3-82. Clear 3-82.
roller to placed the 3478A into local and the Local Lockout placed the 3478A into local and the Local Lockout
the Message is cleared. Message is cleared.
3-83. 3-83. Require
Message (SRQ Message) is independent of all other Message (SRQ Message) is independent of all other
HPIB activity and is sent on a single line called the SRQ HPIB activity and is sent on a single line called the SRQ
The The Line. Its state is eit Line.
false). The 3478A false).
triggers SRQ Message. . This is done SRQ Message
Mask (see paragraph 3-103). Mask (see
annunciator is on when the 3478A requires service. annunciator is on when the 3478A requires service.
(up to .5 3-84. Since more 3-84.
can output the SRQ Message, the devices can be polled can output the SRQ Message, the devices can be polled
by the controller (by a Serial Poll) to determine if the by the controller (by a Serial Poll) to determine if the
3478A (or another d 3478A (or
then outputs a Status Byte (see paragraph 3-85 then outputs a Status Byte (see
Selective shows for what reason the shows for what reason the multimeter requires service.
3-85. 3-85. Status
3478A in 3478A in response to
the same information as the 3478A's Status Register the same information as the 3478A's Status Register
the (see next paragraph), and sets the corresponding bit true (see next paragraph), and sets the corresponding bit true
for any true SRQ condition shown in Table 3-4 for any true SRQ condition shown in
the SRQ Mask is set o the SRQ M
Figure 3-6. Figure 3-6.
78A
the front 3-86. The 3478A can 3-86.
Table 3-4 Table 3-4 is true.
RQ output the Require Service Message (except for bit 7, output the Require Service Message (except for bit 7,
which is set by the Power-On SRQ switch), the 3478A's which is set by the Power-On SRQ switch), the 3478A's
Status Register is used Status Reg
way, only the condition that is set by the mask outputs way, only the condition that is set by the mask outputs
the the SRQ Messa the SRQ Message.
an SRQ Message, but which are not set by the SRQ an SRQ Message, but which are not set by the SRQ
Mask, remain in the Status Register as a true condition. Mask, remain in the Status Register as a true condition.
They will not They will not cause the SRQ Messa
example, suppose the Front Panel SRQ condition is the example, suppose the Front Panel SRQ condition is the
only only one set one set in the
condition is true, but not Front Panel SRQ, no SRQ condition is true, but not Front Panel SRQ, no SRQ
Message Message
Figure 3-6. Figure 3-6. Status Status Byte Byte
3-9 3-9
Local Lockout. All the front panel buttons are All the front panel buttons are
Clear Lockout Lockout and and Set Set Local.
Require Service Service (SRQ). (SRQ). The Require Service
Its state is either true or false (lo her true or false (low=true and high
The 3478A must be must be programmed t
This is done by pro
paragraph 3-103).
Since more than one than one device (on the
another device) requires evice) requires service.
multimeter requires service.
Status Byte. Byte. The Status The Status Byte
response to a Serial Po a Serial Poll. ll. The message has
ask is set or not). r not). The bit is re
The 3478A can require service if a require service if any condition
is true. Since the Since the SRQ Mask must
ister is used to monitor to monitor the condition
ge. Other true Other true conditions that
cause the SRQ Message to be outpu
in the SRQ Mask. SRQ Mask.
TM 11-6625-3071-14 TM 11-6625-3071-14
Local. This This message message
The Require Service
w=true and high = =
programmed to send o send the
by programming the gramming the SRQ SRQ
The front The front panel panel SRQ SRQ
device (on the same Bus) same Bus)
service. The 3478A The 3478A
paragraph 3-85) which ) which
Byte is output is output by by the
The message has
Table 3-4 (whether (whether
The bit is represented in presented in
ny condition in in
SRQ Mask must be set t be set to o
the conditions. s. This This
conditions that can cause can cause
ge to be output. t. For
If the If the Data Ready Data Ready
the
the
For