diff --git a/broker/gen/model/Grid_scan.h b/broker/gen/model/Grid_scan.h
index 79a3e98bb..b21d28bd3 100644
--- a/broker/gen/model/Grid_scan.h
+++ b/broker/gen/model/Grid_scan.h
@@ -12,7 +12,7 @@
/*
* Grid_scan.h
*
- * Definition of a grid scan. May be combined with a goniometer axis: a grid is often collected at a particular head position, and a stationary axis records where that was.
+ * Definition of a grid scan. Combine it with a goniometer axis to state the angle the spindle stood at: send `goniometer` with `step` 0 and the `start` angle of the grid scan, and that angle is written per image into the NXmx sample transformation chain. Without one the spindle is recorded at 0, which says that nobody stated an angle rather than that the spindle stood at 0.
*/
#ifndef Grid_scan_H_
@@ -25,7 +25,7 @@ namespace org::openapitools::server::model
{
///
-/// Definition of a grid scan. May be combined with a goniometer axis: a grid is often collected at a particular head position, and a stationary axis records where that was.
+/// Definition of a grid scan. Combine it with a goniometer axis to state the angle the spindle stood at: send `goniometer` with `step` 0 and the `start` angle of the grid scan, and that angle is written per image into the NXmx sample transformation chain. Without one the spindle is recorded at 0, which says that nobody stated an angle rather than that the spindle stood at 0.
///
class Grid_scan
{
diff --git a/broker/gen/model/Rotation_axis.h b/broker/gen/model/Rotation_axis.h
index 9352cacc8..237066870 100644
--- a/broker/gen/model/Rotation_axis.h
+++ b/broker/gen/model/Rotation_axis.h
@@ -67,7 +67,7 @@ public:
bool nameIsSet() const;
void unsetName();
///
- /// Angle step (per image) in degrees
+ /// Angle step (per image) in degrees. 0 for an axis that does not turn: the axis then records the angle the spindle stood at, which is how a grid scan or a set of stills states its head position.
///
float getStep() const;
void setStep(float const value);
diff --git a/broker/jfjoch_api.yaml b/broker/jfjoch_api.yaml
index 6da578e5a..7b3fe7587 100644
--- a/broker/jfjoch_api.yaml
+++ b/broker/jfjoch_api.yaml
@@ -241,8 +241,11 @@ components:
schemas:
grid_scan:
description: |
- Definition of a grid scan. May be combined with a goniometer axis: a grid is often collected
- at a particular head position, and a stationary axis records where that was.
+ Definition of a grid scan. Combine it with a goniometer axis to state the angle the spindle
+ stood at: send `goniometer` with `step` 0 and the `start` angle of the grid scan, and that
+ angle is written per image into the NXmx sample transformation chain. Without one the
+ spindle is recorded at 0, which says that nobody stated an angle rather than that the
+ spindle stood at 0.
type: object
required:
- n_fast
@@ -298,7 +301,10 @@ components:
type: number
format: float
example: 0.1
- description: Angle step (per image) in degrees
+ description: |
+ Angle step (per image) in degrees. 0 for an axis that does not turn: the axis then
+ records the angle the spindle stood at, which is how a grid scan or a set of stills
+ states its head position.
start:
type: number
format: float
diff --git a/broker/redoc-static.html b/broker/redoc-static.html
index 0ca215c18..5c88781ce 100644
--- a/broker/redoc-static.html
+++ b/broker/redoc-static.html
@@ -472,8 +472,11 @@ the full width of a slit-defined one. [um]
beam_size_y_um
number <float> >= 0
Second element of /entry/instrument/beam/incident_beam_size in NXmx
Vertical size of the X-ray beam where it meets the sample. [um]
object (rotation_axis)
Definition of a crystal rotation axis
-
object (grid_scan)
Definition of a grid scan. May be combined with a goniometer axis: a grid is often collected
-at a particular head position, and a stationary axis records where that was.
+
object (grid_scan)
Definition of a grid scan. Combine it with a goniometer axis to state the angle the spindle
+stood at: send goniometer with step 0 and the start angle of the grid scan, and that
+angle is written per image into the NXmx sample transformation chain. Without one the
+spindle is recorded at 0, which says that nobody stated an angle rather than that the
+spindle stood at 0.
header_appendix
any
Header appendix, added as user_data/user to start ZeroMQ message (can be any valid JSON)
In general, it is not saved in HDF5 file.
However, if values are placed in "hdf5" object, jfjoch_writer will write them in /entry/user of the HDF5 file.
@@ -993,7 +996,7 @@ then image might be replaced in the buffer between calling /images and /image.cb