Next: BACKEND BBC
Up: PAKO Language Internal Help
Previous: Language
Contents
Index
BACKEND
BACKEND name nPart resolution bandwidth fShift
receiverBand [polarization subband|sideband]
BACKEND /CLEAR
Alternative short syntax (only for the backends shown here!):
BACKEND BBC nPart /REC receiverBand [polarization sideband]
BACKEND NBC nPart /REC receiverBand [polarization subband]
BACKEND 4MHz nPart /REC receiverBand [polarization subband]
BACKEND WILMA nPart /REC receiverBand [polarization subband]
BACKEND FTS nPart /REC receiverBand [polarization subband]
BACKEND FTS nPart /FINE /REC receiverBand [polarization subband]
Set up backends for heterodyne receivers.
Character :: name ! name of backend
Integer :: nPart ! (logical) number of backend part
Real :: resolution ! [MHz]
Real :: bandwidth ! [MHz]
Real :: fShift ! frequency shift [MHz]
Character :: receiverBand ! receiver band to connect to backend part
Character :: polarization ! EMIR: polarization to connect to backend part
Character :: subband ! EMIR: subband to connect to backend part
Character :: sideband ! EMIR: sideband to connect to backend part
Choices for (backend) name are:
BBC ! Broad Band Continuum Backend
NBC ! Narrow Band Continuum Backend
4MHz ! filter spectrometers with fixed resolution
WILMA ! autocorrelation spectrometers
FTS ! Fourier Transform Spectrometer
VESPA ! autocorrelator with variable resolution
Choices for receiverBand are (compare RECEIVER command):
E090 E150 E230 E330 HERA1 HERA2
Choices for polarization are (for EMIR; compare RECEIVER command):
Horizontal Vertical
Choices for subband | sideband, when observing with EMIR, are:
LO LI UI UO | LSB USB
LSB and USB apply only to EMIR bands with 8 GHz bandwidth (E090, E230,
and E330) and Backend BBC.
fShift can be used to shift (offset) the backend band within the
receiver band; this only applies to some backends, in particular
VESPA. For VESPA, the range for fShift is much smaller than the 4GHz
subbands of EMIR. For wide-bandwidth backends, fShift is fixed,
corresponding to the frequency pattern of the EMIR subbands and
backend bands. See EMIR and backend documentation.
/CLEAR completely clears the backend setup.
If option /CLEAR is present, all other parameters and options are ignored.
NOTE: EMIR subbands, IF cables, and Backends
The output signals from EMIR are transmitted to the spectrometers and
NBC through 8 IF cables. Each IF cable carries one subband of bandwidth
4 GHz. This subbands are LO, LI, UI, or UO.
NBC, 4MHz, WILMA, and VESPA can only(!) be connected to IF cables 1 to 4.
FTS parts 1 to 4 can also be connected to IF cables 1 to 4.
The command options RECEIVER /HORIZONTAL and RECEIVER /VERTICAL allow
to select up to 4 EMIR subbands that will be transmitted through IF
cables 1 to 4 (compare HELP RECEIVER /HORIZONTAL and the EMIR user
documentation). This selection can include Outer subbands.
In addition, the IF cables 5 to 8 carry the 4 Outer subbands
corresponding to the subbands selected for IF cables 1 to 4. E.g., if
we select for IF 1 to 4:
E230 ver UO E090 ver UI E230 hor UI E090 hor UI
then the IF cables 5 to 8 will transmit:
E230 ver UO E090 ver UO E230 hor UO E090 hor UO.
Only FTS parts 5 to 8 can be connected to IF cables 5 to 8.
BACKEND NBC|WILMA|FTS /DEFAULT will automatically set the maximum
number of backend parts for all available subbands.
BACKEND BBC is completely independant of the sub band selections for
the IF cables.
NOTES:
- for some backends the resolution and/or bandwidth are fixed and the
short syntax can be used. (The full syntax is supported for all backends).
- for VESPA always use the full syntax!
- after changing the receiver configuration: BACKEND /CLEAR is recommended
followed by the backend setup for the new receivers; without that it is
possible that pako will not accept BACKEND commands because of unresolved
conflicts between the RECEIVER and BACKEND setups.
- However, the backend command will automatically try to disconnect
backends that were connected to receiver (sub)bands that are not
connected anymore.
Subsections
Gildas manager
2023-06-01