diff --git a/Makefile b/Makefile
index 9ad027c..1dfbf7d 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ ARCH_FILTER=RHEL%
 
 # additional module dependencies
 REQUIRED+=calc
-# REQUIRED+=s7plcFW
+REQUIRED+=sinqS7plcFW
 
 # General DB files to include in the release
 TEMPLATES += db/sps_status.db
diff --git a/README.md b/README.md
index c7a19a8..bf77737 100644
--- a/README.md
+++ b/README.md
@@ -4,13 +4,25 @@ A collection of standardised SPS databases (or "modules") for interacting with
 the control unit itself and other external hardware.
 
 This makes use of the
-[s7plcFW Epics driver](https://git.psi.ch/epics_driver_modules/s7plcFW) for
+[s7plcFW Epics driver](https://gitea.psi.ch/lin-epics-modules/sinqS7plcFW) for
 communication with the Siemens 7th Generation PLC via the Fetch-Write Protocol.
 
 # Shutter Module
 
-```
-epicsEnvSet("PREFIX", "SQ:INSTRUMENT") # can also be set in runScript call
+This script allows the shutter at the instrument to be opened and closed as
+well as providing access to many status bits and messages.
 
-runScript "$(sinqSPS_DIR)shutter.cmd" "SPS_IP=172.28.101.26, FETCH_DB=2000"
 ```
+epicsEnvSet("INSTR", "SQ:INSTRUMENT:") # can also be set in runScript call
+
+runScript("$(sinqSPS_DIR)shutter.cmd","SPS_IP=172.28.101.26,FETCH_DB=210")
+```
+
+The directly exposed database fields can be found in
+[shutter.substitutions](./templates/shutter.substitutions).
+
+A simplified status value and status message is created from these fields via
+the logic in [shutter.db](./db/shutter.db).
+
+The corresponding nicos device is located at
+[nicos\_sinq/devices/epics/shutter.py](https://gitea.psi.ch/lin-instrument-computers/Nicos/src/branch/release-3.12/nicos_sinq/devices/epics/shutter.py).
diff --git a/db/readbit.db b/db/readbit.db
index 12a4f7a..0ee6569 100644
--- a/db/readbit.db
+++ b/db/readbit.db
@@ -1,4 +1,4 @@
-record(bi,"$(PREFIX):$(SPS_REGISTER_NAME):$(BIT_NAME)")
+record(bi,"$(INSTR)$(SPS_REGISTER_NAME):$(BIT_NAME)")
 {
  field(DTYP, "S7plcFW")
  field(DESC, "$(DESC)")
diff --git a/db/readstring.db b/db/readstring.db
index a700a3d..f625d33 100644
--- a/db/readstring.db
+++ b/db/readstring.db
@@ -1,4 +1,4 @@
-record(stringin, "$(PREFIX):$(SPS_REGISTER_NAME):$(STRING_NAME)-Msg")
+record(stringin, "$(INSTR)$(SPS_REGISTER_NAME):$(STRING_NAME)-Msg")
 {
  field(DTYP, "S7plcFW")
  field(INP,  "@$(SPS_REGISTER_NAME)/$(OFFSET) L=$(LENGTH)")
diff --git a/db/shutter.db b/db/shutter.db
index 23d767e..3ba64c0 100644
--- a/db/shutter.db
+++ b/db/shutter.db
@@ -1,4 +1,4 @@
-record(bo, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER")
+record(bo, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER")
 {
   field(DESC, "Open or close the shutter")
   field(DTYP, "Soft Channel")
@@ -6,40 +6,40 @@ record(bo, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER")
   field(VAL, 0)
   field(ZNAM, "Closed")
   field(ONAM, "Open")
-  field(FLNK, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER-CONTROL PP")
+  field(FLNK, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER-CONTROL PP")
 }
 
 # The Exposed SPS Interface has an open register and a close register. You need
 # to write 1 to the corresponding register to perform said action. This, in
-# combination with "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER", maps the binay 0/1
+# combination with "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER", maps the binay 0/1
 # to writing a 1 to the required register.
-record(seq, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER-CONTROL")
+record(seq, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER-CONTROL")
 {
   field(SELM, "Specified")
-  field(SELL, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER.VAL NPP")
+  field(SELL, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER.VAL NPP")
   field(DO0, 1)
   field(DO1, 1)
-  field(LNK0, "$(PREFIX):$(SPS_REGISTER_NAME):CLOSE-SHUTTER PP")
-  field(LNK1, "$(PREFIX):$(SPS_REGISTER_NAME):OPEN-SHUTTER PP")
+  field(LNK0, "$(INSTR)$(SPS_REGISTER_NAME):CLOSE-SHUTTER PP")
+  field(LNK1, "$(INSTR)$(SPS_REGISTER_NAME):OPEN-SHUTTER PP")
 }
 
-record(calc, "$(PREFIX):$(SPS_REGISTER_NAME):MAP-STATUS")
+record(calc, "$(INSTR)$(SPS_REGISTER_NAME):MAP-STATUS")
 {
   field(DESC, "Maps Status Variables to singular status")
-  field(INPA, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER-READY NPP")
-  field(INPB, "$(PREFIX):$(SPS_REGISTER_NAME):NOT-LOCKED NPP")
-  field(INPC, "$(PREFIX):$(SPS_REGISTER_NAME):REMOTE-OKAY NPP")
-  field(INPD, "$(PREFIX):$(SPS_REGISTER_NAME):PSYS-OK NPP")
-  field(INPE, "$(PREFIX):$(SPS_REGISTER_NAME):EMERGENCY-STOP-OFF NPP")
+  field(INPA, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER-READY NPP")
+  field(INPB, "$(INSTR)$(SPS_REGISTER_NAME):NOT-LOCKED NPP")
+  field(INPC, "$(INSTR)$(SPS_REGISTER_NAME):REMOTE-OKAY NPP")
+  field(INPD, "$(INSTR)$(SPS_REGISTER_NAME):PSYS-OK NPP")
+  field(INPE, "$(INSTR)$(SPS_REGISTER_NAME):EMERGENCY-STOP-OFF NPP")
   field(CALC, "(E=0||B=0)?2:(A=0||D=0)?1:C=0?2:0")
   field(SCAN, ".1 second")
-  field(FLNK, "$(PREFIX):$(SPS_REGISTER_NAME):STATUS PP")
+  field(FLNK, "$(INSTR)$(SPS_REGISTER_NAME):STATUS PP")
 }
 
-record(mbbi, "$(PREFIX):$(SPS_REGISTER_NAME):STATUS")
+record(mbbi, "$(INSTR)$(SPS_REGISTER_NAME):STATUS")
 {
   field(DESC, "Status of Shutter")
-  field(INP, "$(PREFIX):$(SPS_REGISTER_NAME):MAP-STATUS NPP")
+  field(INP, "$(INSTR)$(SPS_REGISTER_NAME):MAP-STATUS NPP")
   field(ZRVL, "0")
   field(ZRST, "Okay")
   field(ONVL, "1")
@@ -48,28 +48,24 @@ record(mbbi, "$(PREFIX):$(SPS_REGISTER_NAME):STATUS")
   field(TWST, "Error")
   field(THVL, "3")
   field(THST, "Unknown")
-  field(FLNK, "$(PREFIX):$(SPS_REGISTER_NAME):STATUS-Msg PP")
+  field(FLNK, "$(INSTR)$(SPS_REGISTER_NAME):STATUS-Msg PP")
 }
 
-record(scalcout, "$(PREFIX):$(SPS_REGISTER_NAME):STATUS-Msg")
+record(scalcout, "$(INSTR)$(SPS_REGISTER_NAME):STATUS-Msg")
 {
   field(DESC, "Status Message")
-  field(INPA, "$(PREFIX):$(SPS_REGISTER_NAME):OPEN NPP")
-  field(INPC, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER-READY NPP")
-  field(INPD, "$(PREFIX):$(SPS_REGISTER_NAME):NOT-LOCKED NPP")
-  field(INPE, "$(PREFIX):$(SPS_REGISTER_NAME):REMOTE-OKAY NPP")
-  field(INPF, "$(PREFIX):$(SPS_REGISTER_NAME):PSYS-OK NPP")
-  field(INPG, "$(PREFIX):$(SPS_REGISTER_NAME):EMERGENCY-STOP-OFF NPP")
-  field(INAA, "$(PREFIX):$(SPS_REGISTER_NAME):OPEN-Msg NPP")
-  field(INBB, "$(PREFIX):$(SPS_REGISTER_NAME):REMOTE-Msg NPP")
-  field(INCC, "$(PREFIX):$(SPS_REGISTER_NAME):SHUTTER-READY-Msg NPP")
-  field(INDD, "$(PREFIX):$(SPS_REGISTER_NAME):EMERGENCY-STOP-Msg NPP")
-  field(INEE, "$(PREFIX):$(SPS_REGISTER_NAME):BLOCKED-Msg NPP")
-  field(INFF, "$(PREFIX):$(SPS_REGISTER_NAME):BLOCKED-REASON-Msg NPP")
-  field(INGG, "$(PREFIX):$(SPS_REGISTER_NAME):PSYS-OK-Msg NPP")
-  # field(CALC, '(C=0||D=0||F=0)?"inv":G=0?DD:E=0?BB:AA')
-  # field(CALC, 'E=0?BB:G=0?DD:AA')
-  # field(CALC, 'G=0?DD:F=0?GG:C=0?CC:(EE[8,10]!="not")?(EE+": "+FF):E=0?BB:AA')
-  # field(CALC, 'G=0?DD:F=0?GG:C=0?CC:D=0?(EE+": "+FF):E=0?BB:AA')
+  field(INPA, "$(INSTR)$(SPS_REGISTER_NAME):OPEN NPP")
+  field(INPC, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER-READY NPP")
+  field(INPD, "$(INSTR)$(SPS_REGISTER_NAME):NOT-LOCKED NPP")
+  field(INPE, "$(INSTR)$(SPS_REGISTER_NAME):REMOTE-OKAY NPP")
+  field(INPF, "$(INSTR)$(SPS_REGISTER_NAME):PSYS-OK NPP")
+  field(INPG, "$(INSTR)$(SPS_REGISTER_NAME):EMERGENCY-STOP-OFF NPP")
+  field(INAA, "$(INSTR)$(SPS_REGISTER_NAME):OPEN-Msg NPP")
+  field(INBB, "$(INSTR)$(SPS_REGISTER_NAME):REMOTE-Msg NPP")
+  field(INCC, "$(INSTR)$(SPS_REGISTER_NAME):SHUTTER-READY-Msg NPP")
+  field(INDD, "$(INSTR)$(SPS_REGISTER_NAME):EMERGENCY-STOP-Msg NPP")
+  field(INEE, "$(INSTR)$(SPS_REGISTER_NAME):BLOCKED-Msg NPP")
+  field(INFF, "$(INSTR)$(SPS_REGISTER_NAME):BLOCKED-REASON-Msg NPP")
+  field(INGG, "$(INSTR)$(SPS_REGISTER_NAME):PSYS-OK-Msg NPP")
   field(CALC, 'G=0?DD:D=0?(EE+": "+FF):F=0?GG:C=0?CC:E=0?BB:AA')
 }
diff --git a/db/sps_status.db b/db/sps_status.db
index 708a3f1..6c483d0 100644
--- a/db/sps_status.db
+++ b/db/sps_status.db
@@ -1,4 +1,4 @@
-record(bi, "$(PREFIX):$(SPS_REGISTER_NAME):ConnStatusFetch")
+record(bi, "$(INSTR)$(SPS_REGISTER_NAME):ConnStatusFetch")
 {
  field(DTYP, "S7plcFW stat")
  field(INP,  "@$(SPS_REGISTER_NAME)")
@@ -7,7 +7,7 @@ record(bi, "$(PREFIX):$(SPS_REGISTER_NAME):ConnStatusFetch")
  field(SCAN, "I/O Intr")
 }
 
-record(bi, "$(PREFIX):$(SPS_REGISTER_NAME):ConnStatusWrite")
+record(bi, "$(INSTR)$(SPS_REGISTER_NAME):ConnStatusWrite")
 {
  field(DTYP, "S7plcFW stat2")
  field(INP,  "@$(SPS_REGISTER_NAME)")
diff --git a/db/writebit.db b/db/writebit.db
index 1eba373..206fe83 100644
--- a/db/writebit.db
+++ b/db/writebit.db
@@ -1,4 +1,4 @@
-record(bo, "$(PREFIX):$(SPS_REGISTER_NAME):$(BIT_NAME)")
+record(bo, "$(INSTR)$(SPS_REGISTER_NAME):$(BIT_NAME)")
 {
  field(DTYP, "S7plcFW")
  field(DESC, "$(DESC)")
diff --git a/scripts/shutter.cmd b/scripts/shutter.cmd
index 508d9e4..626cd54 100644
--- a/scripts/shutter.cmd
+++ b/scripts/shutter.cmd
@@ -1,4 +1,4 @@
-require s7plcFW, wall_e
+require sinqS7plcFW
 
 # s7plcFWConfigure(
 #     # Alias,
@@ -28,10 +28,10 @@ $(SET_SIM_MODE=#) $(SET_SIM_MODE) sleep 3
 s7plcFWConfigure("$(SPS_REGISTER_NAME)", "$(SPS_IP)", "$(FETCH_PORT=2000),1,$(FETCH_DB),0,$(SPS_FETCH_SIZE)", "$(WRITE_PORT=2001),1,$(WRITE_DB=$(FETCH_DB)),0,$(SPS_WRITE_SIZE)", "$(SPS_ENDIANNESS=1)", "$(SPS_RECEIVE_TIMEOUT=1000)", "$(SPS_RECEIVE_DELAY=200)", "0")
 
 # Provides Connection Status PVs
-dbLoadRecords("$(sinqSPS_DB)/sps_status.db", "PREFIX=$(PREFIX), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")
+dbLoadRecords("$(sinqSPS_DB)/sps_status.db", "INSTR=$(INSTR), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")
 
 # Shutter PVs
-dbLoadTemplate("$(sinqSPS_DB)/shutter.substitutions", "PREFIX=$(PREFIX), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")
+dbLoadTemplate("$(sinqSPS_DB)/shutter.substitutions", "INSTR=$(INSTR), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")
 
 # Additional Mapping PVs
-dbLoadRecords("$(sinqSPS_DB)/shutter.db", "PREFIX=$(PREFIX), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")
+dbLoadRecords("$(sinqSPS_DB)/shutter.db", "INSTR=$(INSTR), SPS_REGISTER_NAME=$(SPS_REGISTER_NAME)")