American Magnetics 135 & 136 Liquid Helium Level Instruments (CE-Marked) - Manual (Page 44)

32 Rev. 3
Remote Interface Reference
IEEE-488 Command Set Reference
4.2.4 IEEE-488 Command Set Reference
All commands sent to the Model 135/136 are processed and the Model 135/
136 responds with the answer. If the command is invalid, the Model 135/
136 will respond with -8. All return values are terminated with <LF>
(linefeed) and EOI asserted. For those commands that do not return a
value, the Model 135/136 will echo the command string in the return
message. The Model 135/136 does not implement a full complement of
IEEE 488.2 commands, nor does it conform to the Standard Commands for
Programmable Instruments (SCPI) protocol. These limitations are due to
memory constraints in the microprocessor (subject to change in the
future).
4.2.4.1 Device clear (DCL) command
The Model 135/136 responds to the device clear (DCL) command from a
host IEEE controller. The device clear resets the instrument. The default
units are centimeters and the permanently saved configuration settings
are restored.
4.2.4.2 Commands for controlling the units of measurement
The CM command sets the units of measurement to centimeters and the
INCH command selects inches. The PERCENT command sets the units of
measurement to the percentage of the active sensor length that is
immersed in liquid helium. The units of measurement selected
through the IEEE-488 interface are controlled independently from
the units mode toggle switch used for controlling the front panel
display. The remote units setting is saved in permanent memory by the
SAVE command and is restored at power-up. The UNIT command returns
a one character value (and termination) indicating the current units—C
for centimeters, I for inches, or % for percentage.
Command: CM Function: Sets the units of
measurement to
centimeters
Returns: CM
Command: INCH Function: Sets the units of
measurement to
inches
Returns: INCH
Command: PERCENT Function: Sets the
measurement to % of
active sensor length
Returns: %
Command: UNIT Function: Returns the current
units in use
Returns: C, I, or %