Draft: extract main parameters from output channel

@hammerd would this fix the issue of the main parameters not being accessible from machines not on infiniband, described a the end of https://redmine.xfel.eu/issues/160688?

src/calng/correction_addons/saturation_monitor.py

@@ -73,7 +73,7 @@ class SaturationMonitor(BaseCorrectionAddon):
 
             UINT32_ELEMENT(schema)
             .key("saturationMonitor.alarmCount")
-                .description(
+            .description(
                 "Total number of pixels above alarm threshold. Each pixel "
                 "is only counted once even if it exceeds the threshold in "
                 "multiple frames (/ memory cells = given axis)."
@@ -134,12 +134,52 @@ class SaturationMonitor(BaseCorrectionAddon):
             UINT64_ELEMENT(schema)
             .key(f"{prefix}.frameAxis")
             .displayedName('Multi-frame axis')
-            .description("Axis for frames. Used to take the max over this axis.")
+            .description(
+                "Axis for frames. Used to take the max over this axis.")
             .tags("managed")
             .assignmentOptional()
             .defaultValue(0)
             .reconfigurable()
             .commit(),
+
+            NODE_ELEMENT(schema)
+            .key("saturationMonitor")
+            .commit(),
+
+            BOOL_ELEMENT(schema)
+            .key("saturationMonitor.warning")
+            .readOnly()
+            .commit(),
+
+            BOOL_ELEMENT(schema)
+            .key("saturationMonitor.alarm")
+            .readOnly()
+            .commit(),
+
+            UINT32_ELEMENT(schema)
+            .key("saturationMonitor.warnCount")
+            .description(
+                "Total number of pixels above warning threshold. Each pixel "
+                "is only counted once even if it exceeds the threshold in "
+                "multiple frames (/ memory cells = given axis)."
+            )
+            .readOnly()
+            .commit(),
+
+            UINT32_ELEMENT(schema)
+            .key("saturationMonitor.alarmCount")
+            .description(
+                "Total number of pixels above alarm threshold. Each pixel "
+                "is only counted once even if it exceeds the threshold in "
+                "multiple frames (/ memory cells = given axis)."
+            )
+            .readOnly()
+            .commit(),
+
+            FLOAT_ELEMENT(schema)
+            .key("saturationMonitor.maxValue")
+            .readOnly()
+            .commit(),
         )
 
     def post_correction(self, processed_data, cell_table, pulse_table, output_hash):