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HP 6002A/HP 1000
Buffering
The buffering option for the 6002A EQT should be turned off
until
the
device has been
tested
for valid operation.
:SYEQ,10,UN
will set the 6002A EQT to the unbuffered
mode.
Although the time-out for the 6002A EQT must be a com-
promise for all devices on the HP-IB, the 6002A time-out can
be as short as one second. The time-out is an error condition
for this device.
The 6002A either listens and accepts programming informa-
tion, or an error condition exists (the 6002A hardware is
inoperative). For this reason, it is usually satisfactory to allow
the operating system to handle time-out errors. (The device
configuration
word
defaults to this condition .) From File Man-
ager, a system request may be used to set the time-out
value:
:SYTO,10,100
will set
the
time-out on EQT 10 to one second.
Configuration
The 6002A
is
a device which will need special configuration
on
HP-IB.
Four
ASCII
characters are expected by the power
supply. These characters do not include an end-of-record
terminator.
(The carriage return (CR), linefeed (LF) ter-
minator will confuse
the
6002A.) When an ASCII write re-
quest
(a formatted
"WRITE"
from FORTRAN, for example)
is
performed in the HP 1000, a CRLF is automatically sent as
the record
terminator.
By inserting the underline character
C'_
"
) at the end of each output record, the end-of-record
terminators may be suppressed
.
This method must be used
each
time
a write
request
is made to the 6002A. See the
example
FORTRAN
program in figure 9-4 for more details.
SRQ
is not applicable to
the
6002A. The default SRQ config-
uration is
satisfactory.
DMA is
not usually allocated for the 6002A so the device
configuration word should be checked to see that a DMA
channel is not inadvertantly allocated.
The
I,J,
and P bits of the configuration word are not applica-
ble
to the
6002A, and may be left at their default values
.
9-2
From File Manager,
:CN,17,25E,17000E
"
will assure that LU
17
(the 6002A) is configured correctly.
Remote
The 6002A need not be configured into remote for
programming.
Programming
Because record terminators are not accepted, File Manager
should not be used to check out the power supply.
The HP-IB option (001) is basically a digital-to-analog conver-
ter (DAC) that voltage-programs the power supply's constant
voltage (CV) or constant current (CC) output in
the
high or
low range.
The
DAC automatically provides a voltage-
programming output to the power supply as soon as four
digits are received. This output is retained until the next four
digits are received
.
The DAC is programmed by the mag-
,
---../'
nitude digits in BCD in such a way that 000 equal 00.0% of
full range, 500 equals 50.0% of
full range,
and 999 equals
99.9% of full range.
The magnitude of the constant voltage (CV) or constant
current (CC) output of the power supply is programmed by a
data word comprised of four ASCII characters (digits) re-
ceived in the order shown by figure 9-2. The first digit
specifies range and the next three digits specify the desired
magnitude (percentage of full scale).
01
I
Range
1 or 2
02
03
04
~~-------'r~------_/
Magnitude
000-999
Figure 9-2. 6002A Data Word Format
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