diff --git a/iocBoot/iocUnix/st.cmd b/iocBoot/iocUnix/st.cmd
index 8c0bace4abd3f285931e3026a3ab6d9929a087f7..c8106f37bc9a1a7b355ad673ba689ba6434b2d80 100644
--- a/iocBoot/iocUnix/st.cmd
+++ b/iocBoot/iocUnix/st.cmd
@@ -54,7 +54,7 @@ epicsEnvSet EPICS_CA_MAX_ARRAY_BYTES 64008
 #dbLoadRecords("$(IP)/ipApp/Db/love.db", "P=xxx:,Q=Love_0,C=0,PORT=PORT2,ADDR=1");
 
 # interpolation
-dbLoadRecords("$(CALC)/calcApp/Db/interp.db", "P=xxx:")
+dbLoadRecords("$(CALC)/calcApp/Db/interp.db", "P=xxx:,N=2000")
 
 
 # X-ray Instrumentation Associates Huber Slit Controller
diff --git a/iocBoot/iocvxWorks/st.cmd b/iocBoot/iocvxWorks/st.cmd
index 43c33081c42ca4a48a05e061244b9410db763006..4acf77b9daca44f37fb248f98599e8a9cad8ba0a 100644
--- a/iocBoot/iocvxWorks/st.cmd
+++ b/iocBoot/iocvxWorks/st.cmd
@@ -375,7 +375,7 @@ dbLoadRecords("$(STD)/stdApp/Db/yySseq.db","P=xxx:,S=Sseq3")
 # 4-step measurement
 dbLoadRecords("$(STD)/stdApp/Db/4step.db", "P=xxx:")
 # interpolation
-dbLoadRecords("$(CALC)/calcApp/Db/interp.db", "P=xxx:")
+dbLoadRecords("$(CALC)/calcApp/Db/interp.db", "P=xxx:,N=2000")
 # array test
 dbLoadRecords("$(CALC)/calcApp/Db/arrayTest.db", "P=xxx:,N=2000")