Keyence LK-G: make reading offset and measurement mode configurable

[Tom-Willemsen]

Where?

As an instrument scientist on reflectometers (especially INTER), I would like to be able to disable the Keyence LK-G IOC from attempting to read the offset.

In order to read the offset & measurement modes, the IOC puts the device into "setup" mode, reads the offset, and then puts it back into "measure" mode. The scientists believe that this changing between modes is sometimes causing delays in reading the position, which they believe might have lead to a beamline alingment problem (?).

How?

Make the SCAN for offsets user-configurable - either by an IOC macro or by an autosaved dropdown selection (see e.g. instron for user-configurable scan rates). Scan options should be "5 second" or "Passive".

The OPI should clearly indicate that the offset & measure mode parameters are not scanning - or perhaps hide it entirely - if it is configured not to scan.

Acceptance criteria

• As a user, I can choose to make the Keyence LK-G not scan the OFFSET parameter.
  • This means that the device no longer flicks between "measure" and "setup" modes
• As a user, I can choose to make the Keyence LK-G scan the OFFSET parameter.
• As above but for both measurement mode parameters (should use the same option)
• There are IOC tests for the above

How to Test

verbose instructions for reviewer to test changes
(Add before making a PR)

[Tom-Willemsen]

This has been patched on INTER. For avoidance of doubt the patch applied is:

diff --git a/keylkg.db.bak b/keylkg.db
index f33c652..74a0e24 100644
--- a/keylkg.db.bak
+++ b/keylkg.db
@@ -59,7 +59,7 @@ record(mbbi, "$(P)MEASUREMODE:HEAD:A")
 {
     field(DESC, "Current measurement mode for head A")
     field(DTYP, "stream")
-    field(SCAN, "2 second")
+    field(SCAN, "Passive")
 
     field(INP, "@keylkg.proto getMeasureModeHeadA($(P),ERROR) $(PORT)")
 
@@ -102,7 +102,7 @@ record(mbbi, "$(P)MEASUREMODE:HEAD:B")
 {
     field(DESC, "Current measurement mode for head B")
     field(DTYP, "stream")
-    field(SCAN, "2 second")
+    field(SCAN, "Passive")
 
     field(INP, "@keylkg.proto getMeasureModeHeadB($(P),ERROR) $(PORT)")
 
@@ -173,7 +173,7 @@ record(ai, "$(P)OFFSET:OUTPUT:1")
 {
     field(DESC, "Current Offset for signal: output 1")
     field(DTYP, "stream")
-    field(SCAN, "2 second")
+    field(SCAN, "Passive")
     field(PREC, "4")
     field(EGU, "")
 
@@ -216,7 +216,7 @@ record(ai, "$(P)OFFSET:OUTPUT:2")
 {
     field(DESC, "Current Offset for signal: output 2")
     field(DTYP, "stream")
-    field(SCAN, "2 second")
+    field(SCAN, "Passive")
     field(PREC, "4")
     field(EGU, "")
 

But this ticket should provide a better solution than just blanket-disabling SCAN for these commands