5
Compound Command Header Omission
When several commands having a common header are combined to form a compound command
(e.g.,
:
RANGe:AUTO:R
and
:RANGe:AUTO:B
)
if they are written together in sequence, the common
portion (here,
:
RANGe:AUTO
) can be omitted after its initial occurrence.
This common portion is called the “current path” (analogous to the path concept in computer file storage), and until it
is cleared, the interpretation of subsequent commands presumes that they share the same common portion.
This usage of the current path is shown in the following
example:
Full expression
:RANGE:AUTO:R 0;:RANGE:AUTO:G 0;:RANGE:AUTO:B 0
Compacted
expression
:RANGE:AUTO:R 0; G 0; B 0
This portion becomes the current path, and can be omitted from the messages immediately following.
The current path is cleared when the power is turned on, by a colon “:” at the start of a command, by a colon “*” at
the start of a command, and when a message terminator is detected.
Standard command messages can be executed regardless of the current path. They have no effect upon the
current path.
A colon “:” is not required at the start of the header of a Simple or Compound command. However, to avoid
confusion with abbreviated forms and operating mistakes, we recommend always placing a colon at the start of a
header.
Output Queue and Input Buffer
Input Buffer
The input buffer capacity of the instrument is 1024 bytes.
If 1024 bytes are allowed to accumulate in this buffer so that it becomes full, the LAN interface bus enters the
waiting state until space is cleared in the buffer.
Note: Ensure that the no command ever exceeds 1024 bytes.