Operation of Flag1 and Flag2 on 9-ID





Flag1 is located in the downstream section of 9-ID A (FOE) above ion pump IP109, between the output of the Monochromator and the input to the White Beam Absorber.


Flag2 is located in the first pump station downstream of 9-ID A (FOE), in particular, it is downstream of the horizontal and vertical focussing mirrors.



The mechanical actuators for both flags are MDC BLM-275-4-03 with 100 mm travel. Their mechanical position is indicated on a metric scale located on the cylindrical actuator body. “0 mm” is the most upward position and “100 mm” is the most downward position.



Flag1 is operated by EPICS-motor 9ida:m20.

Flag2 is operated by EPICS-motor 9ida:m22.

Motor parameters are shown in below.

(Note: in the motor setup window the “600 Steps/Rev” reflect the 3:1 gear box)


Flag1 and Flag2 can be accessed from the main EPICS menu “9ida2.adl” through Flags:



Flags        Flag #1                or                     Motors FOE   17-24    Flag 1



Flags        Flag #2                or                     Motors FOE   17-24    Flag 2





The motions of Flag1 and Flag2 conform to the regular coordinate convention for a beamline y-axis with “+” pointing upwards and “-“ pointing downwards.


The top-most mechanical position 0 mm corresponds to an EPICS motor postion of 0 mm

The bottom-most mechanical position 100 mm corresponds to an EPICS motor postion of -100 mm. Soft-limits are set to restrict the motions between -5 mm at the top and -95 mm at the bottom,





all valid motor position are between -5 mm at the top and -95 mm at the bottom




With the actuator at a mechanical position “x.x mm” set the motor position in EPICS to ”–x.x