REMOTE OPERATION
5-7
Program data
Data can take many forms, as follows:
Decimal Numeric Data is a flexible numeric format which encompasses integer, fixed
point and floating point (mantissa and exponent) representations. Data is rounded to a
resolution appropriate to the function. Decimal data can, in most cases, be followed by
the appropriate units. If no units are present, the specified default units are assumed.
Character Data is an alphanumeric word.
String Data consists of a number of 7-bit ASCII characters enclosed in quotes; either a
pair of single ('ASCII 39') or double ("ASCII 34") quotes may be used.
Some commands can accept Multiple Data items which are separated by commas, for
example MODE FM,AM.
Message exchange protocol
The controller should not attempt to read a response until it has sent the entire query message
(terminated by EOM). Also, it should not start to send a new message until it has read the entire
response (terminated by EOM). The query message may contain more than one query message
unit, but only one response message (containing several response message units) is generated.
Failure to follow the protocol will generate a query error:
INTERRUPTED (error 450) occurs when the controller starts to send a new message
before having read the response to a preceding query.
UNTERMINATED (error 451) occurs when the controller attempts to read a response
without having sent a query.
DEADLOCK (error 452) can only occur if the input and output buffers are both filled by
the controller having sent an extra long message containing several query message units.
These instruments have an input buffer of 256 characters and an output buffer of 256 characters.
Remote/local operation
When the instrument is addressed by the controller it will enter its remote mode and the screen will
display the
[REM]
annunciator. Only one key, the softkey
[Go To Local],
will have any effect
.
Pressing this key returns the unit to normal manual operation, unless Local Lockout has been
asserted by the controller.
Common commands and queries (IEEE 488.2)
The IEEE 488.2 standard defines a set of common commands and queries which implement
common system functions.
Common command and query mnemonics are preceded by an asterisk (*) to distinguish them from
device-dependent data such as instrument programming strings. The following common
commands and queries are implemented in the instrument:
