American Magnetics 430, Инструкции по установке, эксплуатации и обслуживанию

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142 R
EV
9
A
MERICAN
M
AGNETICS
, I
NC
. R
EMOTE
I
NTERFACE
R
EFERENCE
: P
ROGRAMMING
O
VERVIEW
NOTE
The *OPC command historically is designed to generate an SRQ
which can be monitored by a serial poll over a GPIB interface,
which operates outside of the normal command queue. Since a
GPIB interface is not available in the Model 430, the *OPC
command has limited value (as it would require polling the status
registers
using the command queue) and should be ignored in
favor of the *OPC? query documented below for the serial and
Ethernet interfaces.
U
SING THE
*OPC?
Q
UERY
The
*OPC?
query is similar to the
*OPC
command, but instead of
setting the “Operation Complete” bit of the Standard Event
register, the
*OPC?
query returns a “1” (plus termination
characters) to the appropriate output buffer when executed.
Using
*OPC?
is a simple solution for determining completed
remote command execution (because
commands
do not send a
reply). It is also unambiguous during simultaneous serial and
Ethernet operation since the result is returned directly to the
requesting communication interface.
An example of a sequence of commands using the
*OPC?
query
to handshake is the following:
CONF:CURR:TARG 50.0;
CONF:RAMP:RATE:CURR 1,0.1,80.0;
CONF:VOLT:LIM 5.0;
*OPC?;
The above example sets the target current to 50.0 A, the ramp
rate segment #1 to 0.1 A/s up to 80.0 A, the voltage limit to 5.0 V,
and sends as the fourth command the
*OPC?
query for
determining when execution all of the commands (including
*OPC?
) is completed. The
*OPC?
query will return a “1” to the
requesting interface when it executes.