Omega CL3001, Руководство пользователя, Страница: 51 / 104

RANGE?
This command instructs the CL3001 to return the present
DC voltage output range.
d) Interface Messages (IEEE-488)
Interface messages manage traffic on the IEEE-488
interface bus. Device addressing and clearing, data
handshaking, and commands to place status bytes on the
bus are all directed by interface messages. Some of the
interface messages occur as state transitions of dedicated
control lines. The rest of the interface messages are sent
over the data lines with the ATN signal true. All device-
dependent and common commands are sent over the
data lines with the ATN signal false.
An important thing to note about interface messages is
that, unlike device-dependent and common commands,
interface messages are not sent literally (in a direct way).
They are converted to parallel signal levels on the bus data
and control lines.
IEEE-488 standards define interface messages which are
handled automatically in most cases.
e) Compound Commands
A compound command is two or more commands placed
on a single command line separated from each other with
semicolons. For example, consider the following two
individual commands:
OUT 1 V
OPER
These could be combined into the compound command:
OUT 1 V; OPER
These commands instruct the CL3001 to source 1 V DC,
and then go into operate mode.
f) Overlapped Commands
Commands that begin execution but require slightly more
time than the normal communication command/response
interval to complete are called overlapped commands.
This is because they can be overlapped by receipt the
next command before they have been completed.
The detailed command descriptions in section 10 show a
check mark T beside Overlapped for overlapped
commands.
Use the command *WAI to wait until the overlapped
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