diff --git a/devsupApp/src/dbdset.c b/devsupApp/src/dbdset.c
index 9fd4ea3..12461d9 100644
--- a/devsupApp/src/dbdset.c
+++ b/devsupApp/src/dbdset.c
@@ -15,6 +15,7 @@
 #include <recGbl.h>
 #include <alarm.h>
 #include <ellLib.h>
+#include <dbScan.h>
 #include <cantProceed.h>
 
 #include "pydevsup.h"
@@ -31,6 +32,9 @@ typedef struct {
     PyObject *pyrecord;
     PyObject *support;
 
+    int allowscan;
+    IOSCANPVT scan;
+
     PyObject *reason;
 } pyDevice;
 
@@ -49,6 +53,7 @@ static long parse_link(dbCommon *prec, const char* src)
         return -1;
 
     if(!PyArg_ParseTuple(ret, "OO", &priv->pyrecord, &priv->support)) {
+        priv->pyrecord = priv->support = NULL; /* paranoia */
         Py_DECREF(ret);
         return -1;
     }
@@ -98,6 +103,20 @@ static long process_common(dbCommon *prec)
     return 0;
 }
 
+static int allow_ioscan(pyDevice *priv)
+{
+    PyObject *ret = PyObject_CallMethod(priv->support, "allowScan", "O", priv->pyrecord);
+    if(!ret || !PyObject_IsTrue(ret)) {
+        PyErr_Print();
+        PyErr_Clear();
+        Py_XDECREF(ret);
+        return 0;
+    } else {
+        Py_DECREF(ret);
+        return 1;
+    }
+}
+
 static long init_record(dbCommon *prec)
 {
     return 0;
@@ -146,6 +165,7 @@ static long add_record(dbCommon *prec)
         priv = callocMustSucceed(1, sizeof(*priv), "init_record");
         priv->precord = prec;
         priv->plink = ent.pfield;
+        scanIoInit(&priv->scan);
 
         if(priv->plink->type != INST_IO) {
             fprintf(stderr, "%s: Has invalid link type %d\n", prec->name, priv->plink->type);
@@ -194,7 +214,7 @@ static long del_record(dbCommon *prec)
     pyDevice *priv=prec->dpvt;
     PyGILState_STATE pystate;
 
-    if(!priv)
+    if(!priv || !priv->support)
         return 0;
 
     pystate = PyGILState_Ensure();
@@ -212,6 +232,22 @@ static long del_record(dbCommon *prec)
     return 0;
 }
 
+static long get_iointr_info(int dir, dbCommon *prec, IOSCANPVT *scan)
+{
+    pyDevice *priv=prec->dpvt;
+    if(!priv || !priv->support)
+        return 0;
+
+    if(dir==0) {
+        if(!allow_ioscan(priv))
+            return S_db_Blocked;
+        priv->allowscan = 1;
+    } else
+        priv->allowscan = 0;
+    *scan = priv->scan;
+    return 0;
+}
+
 static long process_record(dbCommon *prec)
 {
     pyDevice *priv = prec->dpvt;
@@ -273,14 +309,28 @@ typedef struct {
     DEVSUPFUN proc;
 } dset5;
 
-static dset5 pydevsupCom = {{5, NULL, (DEVSUPFUN)&init, (DEVSUPFUN)&init_record, NULL}, (DEVSUPFUN)&process_record};
-static dset5 pydevsupCom2 = {{5, NULL, (DEVSUPFUN)&init, (DEVSUPFUN)&init_record2, NULL}, (DEVSUPFUN)&process_record};
+static dset5 pydevsupCom = {{5, NULL, (DEVSUPFUN)&init,
+                             (DEVSUPFUN)&init_record,
+                             (DEVSUPFUN)&get_iointr_info},
+                            (DEVSUPFUN)&process_record};
+static dset5 pydevsupCom2 = {{5, NULL, (DEVSUPFUN)&init,
+                              (DEVSUPFUN)&init_record2,
+                              (DEVSUPFUN)&get_iointr_info},
+                             (DEVSUPFUN)&process_record};
 
 int isPyRecord(dbCommon *prec)
 {
     return prec->dset==(dset*)&pydevsupCom || prec->dset==(dset*)&pydevsupCom2;
 }
 
+int canIOScanRecord(dbCommon *prec)
+{
+    pyDevice *priv=prec->dpvt;
+    if(isPyRecord(prec))
+        return 0;
+    return priv->allowscan;
+}
+
 /* Called with GIL locked */
 void pyDBD_cleanup(void)
 {
@@ -300,12 +350,9 @@ void pyDBD_cleanup(void)
 
         /* cleanup and dealloc */
 
-        if(priv->support)
-            Py_DECREF(priv->support);
-        if(priv->pyrecord)
-            Py_DECREF(priv->pyrecord);
-        if(priv->reason)
-            Py_DECREF(priv->reason);
+        Py_XDECREF(priv->support);
+        Py_XDECREF(priv->pyrecord);
+        Py_XDECREF(priv->reason);
         priv->support = priv->pyrecord = priv->reason = NULL;
 
         free(priv);
diff --git a/devsupApp/src/dbrec.c b/devsupApp/src/dbrec.c
index b6e0d92..714d8f5 100644
--- a/devsupApp/src/dbrec.c
+++ b/devsupApp/src/dbrec.c
@@ -18,6 +18,7 @@ typedef struct {
     PyObject_HEAD
 
     DBENTRY entry;
+    int ispyrec;
 } pyRecord;
 
 static void pyRecord_dealloc(pyRecord *self)
@@ -33,6 +34,7 @@ static PyObject* pyRecord_new(PyTypeObject *type, PyObject *args, PyObject *kws)
     self = (pyRecord*)type->tp_alloc(type, 0);
     if(self) {
         dbInitEntry(pdbbase, &self->entry);
+        self->ispyrec = isPyRecord(self->entry.precnode->precord);
     }
     return (PyObject*)self;
 }
@@ -50,6 +52,11 @@ static int pyRecord_Init(pyRecord *self, PyObject *args, PyObject *kws)
     return 0;
 }
 
+static PyObject* pyRecord_ispyrec(pyRecord *self)
+{
+    return PyBool_FromLong(self->ispyrec);
+}
+
 static int pyRecord_compare(pyRecord *A, pyRecord *B)
 {
     dbCommon *a=A->entry.precnode->precord,
@@ -124,11 +131,12 @@ static PyObject* pyRecord_scan(pyRecord *self, PyObject *args, PyObject *kws)
 {
     dbCommon *prec = self->entry.precnode->precord;
 
-    static char* names[] = {"sync", "reason", NULL};
+    static char* names[] = {"sync", "reason", "force", NULL};
+    unsigned int force = 0;
     PyObject *reason = Py_None;
     PyObject *sync = Py_False;
 
-    if(!PyArg_ParseTupleAndKeywords(args, kws, "|OO", names, &sync, &reason))
+    if(!PyArg_ParseTupleAndKeywords(args, kws, "|OOI", names, &sync, &reason, &force))
         return NULL;
 
     if(!PyObject_IsTrue(sync)) {
@@ -136,20 +144,32 @@ static PyObject* pyRecord_scan(pyRecord *self, PyObject *args, PyObject *kws)
         Py_RETURN_NONE;
 
     } else {
-        long ret;
+        long ret=-1;
+        int ran=1;
         setReasonPyRecord(prec, reason);
 
         Py_BEGIN_ALLOW_THREADS {
 
             dbScanLock(prec);
-            ret = dbProcess(prec);
+            if(force==1
+               || (force==0 && prec->scan==menuScanPassive)
+               || (force==2 && prec->scan==menuScanI_O_Intr && canIOScanRecord(prec)))
+            {
+                ran = 1;
+                ret = dbProcess(prec);
+            }
             dbScanUnlock(prec);
 
         } Py_END_ALLOW_THREADS
 
         clearReasonPyRecord(prec);
 
-        return PyLong_FromLong(ret);
+        if(ran)
+            return PyLong_FromLong(ret);
+        else {
+            PyErr_SetNone(PyExc_RuntimeError);
+            return NULL;
+        }
     }
 }
 
@@ -181,7 +201,7 @@ static PyObject *pyRecord_asyncFinish(pyRecord *self, PyObject *args, PyObject *
         return NULL;
     }
 
-    Py_INCREF(self);
+    Py_INCREF(self); /* necessary? */
 
     setReasonPyRecord(prec, reason);
 
@@ -213,6 +233,8 @@ static PyObject *pyRecord_asyncFinish(pyRecord *self, PyObject *args, PyObject *
 static PyMethodDef pyRecord_methods[] = {
     {"name", (PyCFunction)pyRecord_name, METH_NOARGS,
      "Return record name string"},
+    {"isPyRecord", (PyCFunction)pyRecord_ispyrec, METH_NOARGS,
+     "Is this record using Python Device."},
     {"info", (PyCFunction)pyRecord_info, METH_VARARGS,
      "Lookup info name\ninfo(name, def=None)"},
     {"infos", (PyCFunction)pyRecord_infos, METH_NOARGS,
diff --git a/devsupApp/src/pydevsup.h b/devsupApp/src/pydevsup.h
index 6539d70..cdfbda2 100644
--- a/devsupApp/src/pydevsup.h
+++ b/devsupApp/src/pydevsup.h
@@ -11,6 +11,7 @@ int pyRecord_prepare(void);
 void pyRecord_setup(PyObject *module);
 
 int isPyRecord(dbCommon *);
+int canIOScanRecord(dbCommon *);
 int setReasonPyRecord(dbCommon *, PyObject *);
 int clearReasonPyRecord(dbCommon *);