Counters#
SPEC data file header control lines #J and #j describe the relationship
between counter names (#J) and mnemonics (#j). The lines
are numbered with a sequential index (starting at 0) to keep the line
lengths within page limits.
When both types are present in the scan’s header, such as this example:
1#J0 seconds I0 I00 USAXS_PD TR_diode
2#j0 sec I0 I00 upd2 trd
then /SCAN/counter_cross_reference (a NXnote [1] group) is
written. The fields of the group are the mnemonics and the values are the
names.
1counter_cross_reference:NXnote
2 @NX_class = "NXnote"
3 @comment = "keys are SPEC counter mnemonics, values are SPEC counter names"
4 @description = "cross-reference SPEC counter mnemonics and names"
5 I0:NX_CHAR = [b'I0']
6 I00:NX_CHAR = [b'I00']
7 sec:NX_CHAR = [b'seconds']
8 trd:NX_CHAR = [b'TR_diode']
9 upd2:NX_CHAR = [b'USAXS_PD']