diff --git a/include/trick/CheckPointRestart.hh b/include/trick/CheckPointRestart.hh
index 4201d7464..8c0a597c6 100644
--- a/include/trick/CheckPointRestart.hh
+++ b/include/trick/CheckPointRestart.hh
@@ -22,6 +22,10 @@ namespace Trick {
      */
     class CheckPointRestart : public Trick::Scheduler {
 
+        private:
+            /** Flag to track if an automatic freeze has been triggered */
+            bool auto_freeze = false;                               /* ** */
+
         protected:
             /** queue to hold jobs to be called before a checkpoint is dumped. */
             Trick::ScheduledJobQueue checkpoint_queue ;              /* ** */
diff --git a/include/trick/sim_mode.h b/include/trick/sim_mode.h
index 1bdbd2ace..51ff2bd76 100644
--- a/include/trick/sim_mode.h
+++ b/include/trick/sim_mode.h
@@ -14,6 +14,10 @@
 #ifndef SIMMODE_HH
 #define SIMMODE_HH
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef enum {
 
     NoCmd = 0 ,         /* NoCmd */
@@ -38,4 +42,10 @@ typedef enum {
 
 } SIM_MODE ;
 
+const char * simModeCharString(SIM_MODE mode);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/test/SIM_checkpoint_data_recording/RUN_test/dump.py b/test/SIM_checkpoint_data_recording/RUN_test/dump.py
index 749d69d4a..37d75acc6 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo.dr").read())
     
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test1/dump.py b/test/SIM_checkpoint_data_recording/RUN_test1/dump.py
index 749d69d4a..37d75acc6 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test1/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test1/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo.dr").read())
     
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test1/ref_log_foo.csv b/test/SIM_checkpoint_data_recording/RUN_test1/ref_log_foo.csv
index 37c97556b..75a5c16e7 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test1/ref_log_foo.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test1/ref_log_foo.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.a {1},testSimObject.my_foo.b {1}
+                   5,6,12
                  5.1,6,12
                  5.2,6,12
                  5.3,6,12
diff --git a/test/SIM_checkpoint_data_recording/RUN_test1/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test1/unit_test.py
index d5b6008cb..3bce5e67f 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test1/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test1/unit_test.py
@@ -1,8 +1,28 @@
 import trick
+from threading import Timer
 
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test1/chkpnt_5.000000")') # This checkpoint has data recording
+    chkpnt_path = "RUN_test1/chkpnt_5.000000"
+    load_checkpoint_at(chkpnt_path, 5.0)
+
     trick.stop(10.0)
 
 if __name__ == "__main__":
diff --git a/test/SIM_checkpoint_data_recording/RUN_test2/dump.py b/test/SIM_checkpoint_data_recording/RUN_test2/dump.py
index d05fc5326..fc0b6e434 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test2/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test2/dump.py
@@ -1,10 +1,28 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():    
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test2/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test2/unit_test.py
index 8ba141c1c..de342fd2d 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test2/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test2/unit_test.py
@@ -1,9 +1,28 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     exec(open("Modified_data/foo.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test2/chkpnt_5.000000")') # this checkpoint does not contain data recording
+    load_checkpoint_at("RUN_test2/chkpnt_5.000000", 5.0) # this checkpoint does not contain data recording
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test3/dump.py b/test/SIM_checkpoint_data_recording/RUN_test3/dump.py
index 749d69d4a..37d75acc6 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test3/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test3/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo.dr").read())
     
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test3/ref_log_foo.csv b/test/SIM_checkpoint_data_recording/RUN_test3/ref_log_foo.csv
index 37c97556b..75a5c16e7 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test3/ref_log_foo.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test3/ref_log_foo.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.a {1},testSimObject.my_foo.b {1}
+                   5,6,12
                  5.1,6,12
                  5.2,6,12
                  5.3,6,12
diff --git a/test/SIM_checkpoint_data_recording/RUN_test3/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test3/unit_test.py
index c91faf0e5..d48ba0cc5 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test3/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test3/unit_test.py
@@ -1,10 +1,29 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     
     exec(open("Modified_data/foo.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test3/chkpnt_5.000000")') # contains data recording
+    load_checkpoint_at("RUN_test3/chkpnt_5.000000", 5.0) # contains data recording
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test4/dump.py b/test/SIM_checkpoint_data_recording/RUN_test4/dump.py
index 00df66fd6..79fc43784 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test4/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test4/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo.dr").read())
     
-    trick.checkpoint(2.0)
+    checkpoint(2.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test4/ref_log_foo.csv b/test/SIM_checkpoint_data_recording/RUN_test4/ref_log_foo.csv
index 13327df84..b70298737 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test4/ref_log_foo.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test4/ref_log_foo.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.a {1},testSimObject.my_foo.b {1}
+                   2,3,6
                  2.1,3,6
                  2.2,3,6
                  2.3,3,6
diff --git a/test/SIM_checkpoint_data_recording/RUN_test4/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test4/unit_test.py
index f07baf1d1..f9efd12c7 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test4/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test4/unit_test.py
@@ -1,10 +1,29 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     
     exec(open("Modified_data/foo.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test4/chkpnt_2.000000")') # contains data recording, starts at t=2
+    load_checkpoint_at("RUN_test4/chkpnt_2.000000", 5.0) # contains data recording, starts at t=2
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test5/dump.py b/test/SIM_checkpoint_data_recording/RUN_test5/dump.py
index 565a891b6..4bbbcd13f 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test5/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test5/dump.py
@@ -1,12 +1,29 @@
 import trick
-from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo.dr").read())
     
-    trick.checkpoint(7.0)
+    checkpoint(7.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test5/ref_log_foo.csv b/test/SIM_checkpoint_data_recording/RUN_test5/ref_log_foo.csv
index 306de1b40..490689651 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test5/ref_log_foo.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test5/ref_log_foo.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.a {1},testSimObject.my_foo.b {1}
+                   7,8,16
                  7.1,8,16
                  7.2,8,16
                  7.3,8,16
diff --git a/test/SIM_checkpoint_data_recording/RUN_test5/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test5/unit_test.py
index 649cb370a..01ec002fe 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test5/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test5/unit_test.py
@@ -1,10 +1,29 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     
     exec(open("Modified_data/foo.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test5/chkpnt_7.000000")') # contains data recording, starts at t=7
+    load_checkpoint_at("RUN_test5/chkpnt_7.000000", 5.0) # contains data recording, starts at t=7
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test6/dump.py b/test/SIM_checkpoint_data_recording/RUN_test6/dump.py
index 7b7db62af..9b7667569 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test6/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test6/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/foo2.dr").read())
     
-    trick.checkpoint(7.0)
+    checkpoint(7.0)
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test6/ref_log_foo2.csv b/test/SIM_checkpoint_data_recording/RUN_test6/ref_log_foo2.csv
index f7b15a2b7..2ee326def 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test6/ref_log_foo2.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test6/ref_log_foo2.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.b {1}
+                   7,16
                    8,18
                    9,20
                   10,22
diff --git a/test/SIM_checkpoint_data_recording/RUN_test6/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test6/unit_test.py
index f5b5f315c..169620557 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test6/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test6/unit_test.py
@@ -1,11 +1,30 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     
     exec(open("Modified_data/foo.dr").read())
 
     # trick.checkpoint(7.0)
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test6/chkpnt_7.000000")') # contains data recording, starts at t=7
+    load_checkpoint_at("RUN_test6/chkpnt_7.000000", 5.0) # contains data recording, starts at t=7
 
     trick.stop(10.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test7/dump.py b/test/SIM_checkpoint_data_recording/RUN_test7/dump.py
index 749a0c6e6..a7c39a7ac 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test7/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test7/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/fooChange.dr").read())
     
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(20.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test7/ref_log_fooChange.csv b/test/SIM_checkpoint_data_recording/RUN_test7/ref_log_fooChange.csv
index 31352b3bf..6abcd599d 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test7/ref_log_fooChange.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test7/ref_log_fooChange.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.a {1},testSimObject.my_foo.b {1},testSimObject.my_foo.q {1}
+                   5,6,12,2
                    8,9,18,3
                   11,12,24,4
                   14,15,30,5
diff --git a/test/SIM_checkpoint_data_recording/RUN_test7/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test7/unit_test.py
index 2076f610e..e90a0d5ab 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test7/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test7/unit_test.py
@@ -1,9 +1,28 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     exec(open("Modified_data/fooChange.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test7/chkpnt_5.000000")') # this checkpoint does not contain data recording
+    load_checkpoint_at("RUN_test7/chkpnt_5.000000", 5.0) # this checkpoint does not contain data recording
 
     trick.stop(20.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test8/dump.py b/test/SIM_checkpoint_data_recording/RUN_test8/dump.py
index a63985c11..9c8dd16c1 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test8/dump.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test8/dump.py
@@ -1,12 +1,30 @@
 import trick
 from trick.unit_test import *
+from threading import Timer
 
 # This was just here for convenience to dump the checkpoints.
 
+def dump_checkpoint(sim_time): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.checkpoint()
+        trick.exec_run()
+    elif cur_time > sim_time:
+        return
+    else:        
+        Timer(0.1, dump_checkpoint, (sim_time,)).start()
+
+def checkpoint(time):
+    Timer(1.0, dump_checkpoint, (time,)).start()
+
+    trick.freeze(time)
+
 def main():
     exec(open("Modified_data/fooChange2.dr").read())
     
-    trick.checkpoint(5.0)
+    checkpoint(5.0)
 
     trick.stop(20.0)
 
diff --git a/test/SIM_checkpoint_data_recording/RUN_test8/ref_log_fooChange2.csv b/test/SIM_checkpoint_data_recording/RUN_test8/ref_log_fooChange2.csv
index 5692f5342..96eba9af7 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test8/ref_log_fooChange2.csv
+++ b/test/SIM_checkpoint_data_recording/RUN_test8/ref_log_fooChange2.csv
@@ -1,4 +1,5 @@
 sys.exec.out.time {s},testSimObject.my_foo.q {1}
+                   5,2
                    8,3
                   11,4
                   14,5
diff --git a/test/SIM_checkpoint_data_recording/RUN_test8/unit_test.py b/test/SIM_checkpoint_data_recording/RUN_test8/unit_test.py
index 1a0d0c5cb..a502f72a2 100644
--- a/test/SIM_checkpoint_data_recording/RUN_test8/unit_test.py
+++ b/test/SIM_checkpoint_data_recording/RUN_test8/unit_test.py
@@ -1,9 +1,28 @@
 import trick
+from threading import Timer
+
+def load_checkpoint(path, sim_time, tries=10): 
+    mode = trick.exec_get_mode()
+    cur_time = trick.exec_get_sim_time()
+
+    if(mode == 1 and cur_time == sim_time):
+        trick.load_checkpoint(path)
+        trick.exec_run()
+    elif cur_time > sim_time or tries <= 0:
+        print("Issue with loading checkpoint from input file!")
+        return
+    else:
+        Timer(0.1, load_checkpoint, (path, sim_time, tries - 1,)).start()
+
+def load_checkpoint_at(path, time):
+    Timer(1.0, load_checkpoint, (path, time)).start()
+    
+    trick.freeze(time)
 
 def main():
     exec(open("Modified_data/fooChange2.dr").read())
 
-    trick.add_read(5.0, 'trick.load_checkpoint("RUN_test8/chkpnt_5.000000")') # this checkpoint does not contain data recording
+    load_checkpoint_at("RUN_test8/chkpnt_5.000000", 5.0) # this checkpoint does not contain data recording
 
     trick.stop(20.0)
 
diff --git a/test/SIM_stls/RUN_test/setup.py b/test/SIM_stls/RUN_test/setup.py
index 208d871f9..03bc6ddcf 100644
--- a/test/SIM_stls/RUN_test/setup.py
+++ b/test/SIM_stls/RUN_test/setup.py
@@ -5,7 +5,7 @@ def main():
     trick.exec_set_job_onoff("the_object.stlc.test", 1, False)
     trick.exec_set_job_onoff("the_object.stlc.print", 1, False)
 
-    trick.add_read( 0.5, 'trick.checkpoint("chkpnt_in")')
+    trick.checkpoint(0.1)
 
     trick.exec_set_freeze_frame(0.10)
     trick.stop(1.0)
diff --git a/test/SIM_stls/RUN_test/unit_test.py b/test/SIM_stls/RUN_test/unit_test.py
index 16c31069f..05ce98843 100644
--- a/test/SIM_stls/RUN_test/unit_test.py
+++ b/test/SIM_stls/RUN_test/unit_test.py
@@ -3,7 +3,7 @@
 
 def main():
 
-    trick.load_checkpoint("RUN_test/chkpnt_in")
+    trick.load_checkpoint("RUN_test/chkpnt_0.100000")
     trick.load_checkpoint_job()
 
     trick.exec_set_job_onoff("the_object.stlc.addData", 1, False)
diff --git a/trick_source/sim_services/CheckPointRestart/CheckPointRestart.cpp b/trick_source/sim_services/CheckPointRestart/CheckPointRestart.cpp
index 002f12896..4c60d15e4 100644
--- a/trick_source/sim_services/CheckPointRestart/CheckPointRestart.cpp
+++ b/trick_source/sim_services/CheckPointRestart/CheckPointRestart.cpp
@@ -19,6 +19,7 @@
 #include "trick/message_proto.h"
 #include "trick/message_type.h"
 #include "trick/TrickConstant.hh"
+#include "trick/sim_mode.h"
 
 Trick::CheckPointRestart * the_cpr ;
 
@@ -109,6 +110,11 @@ int Trick::CheckPointRestart::find_write_checkpoint_jobs(std::string sim_object_
     return(0) ;
 }
 
+/**
+ * @brief Schedule a checkpoint to be written at a given time.
+ * @param in_time The time the checkpoint should be dumped
+ * @see write_checkpoint() 
+ */
 int Trick::CheckPointRestart::checkpoint(double in_time) {
 
     long long curr_time = exec_get_time_tics() ;
@@ -121,6 +127,8 @@ int Trick::CheckPointRestart::checkpoint(double in_time) {
         if ( new_time < write_checkpoint_job->next_tics ) {
             write_checkpoint_job->next_tics = new_time ;
         }
+        
+        the_exec->freeze(in_time);
         //std::cout << "\033[33mSET CHECKPOINT TIME " << in_time << " " << new_time << "\033[0m" << std::endl ;
     } else {
         message_publish(MSG_ERROR, "Checkpoint time specified in the past. specified %f, current_time %f\n",
@@ -171,6 +179,19 @@ int Trick::CheckPointRestart::do_checkpoint(std::string file_name, bool print_st
 
     JobData * curr_job ;
     pid_t pid;
+    SIM_MODE mode;
+
+    mode = the_exec->get_mode();
+
+    if (mode == Run) {
+        std::string msg_format  = "WARNING: Saving a checkpoint outside of 'Freeze Mode' causes undefined behavior. ";
+                    msg_format += "Current Mode: %s (%d)\n";
+        message_publish(MSG_WARNING, msg_format.c_str(),
+                        simModeCharString(mode), mode);
+
+        return 0;
+    }
+    
 
     if ( ! file_name.compare("") ) {
         std::stringstream file_name_stream ;
@@ -227,6 +248,10 @@ int Trick::CheckPointRestart::do_checkpoint(std::string file_name, bool print_st
     return 0 ;
 }
 
+/** 
+ * @brief Writes a scheduled checkpoint if it is the correct time. 
+ * @see checkpoint(double in_time)
+ */
 int Trick::CheckPointRestart::write_checkpoint() {
 
     long long curr_time = exec_get_time_tics() ;
@@ -252,6 +277,7 @@ int Trick::CheckPointRestart::write_checkpoint() {
 
         checkpoint( chk_name_stream.str() );
 
+		the_exec->run();
     }
 
     return(0) ;
@@ -293,6 +319,19 @@ int Trick::CheckPointRestart::safestore_checkpoint() {
 }
 
 void Trick::CheckPointRestart::load_checkpoint(std::string file_name) {
+    SIM_MODE mode = the_exec->get_mode();
+
+    if (mode == Run) {
+        std::string msg_format  = "WARNING: Loading a checkpoint outside of 'Freeze Mode' causes undefined behavior. ";
+                    msg_format += "Current Mode: %s (%d)\n";
+        
+        message_publish(MSG_WARNING, msg_format.c_str(),
+                        file_name.c_str(), simModeCharString(mode), mode);
+        
+        the_exec->freeze();
+        auto_freeze = true;
+    } 
+        
     load_checkpoint_file_name = file_name ;
 }
 
@@ -306,7 +345,7 @@ int Trick::CheckPointRestart::load_checkpoint_job() {
     JobData * curr_job ;
     struct stat temp_buf ;
 
-    if ( ! load_checkpoint_file_name.empty() ) {
+    if ( ! load_checkpoint_file_name.empty() && the_exec->get_mode() != Run) {
 
         if ( stat( load_checkpoint_file_name.c_str() , &temp_buf) == 0 ) {
             preload_checkpoint_queue.reset_curr_index() ;
@@ -338,6 +377,7 @@ int Trick::CheckPointRestart::load_checkpoint_job() {
             message_publish(MSG_INFO, "Could not find checkpoint file %s.\n", load_checkpoint_file_name.c_str()) ;
         }
         load_checkpoint_file_name.clear() ;
+        if(auto_freeze)  the_exec->run();
     }
 
     return(0) ;
diff --git a/trick_source/sim_services/Executive/Executive_freeze_loop.cpp b/trick_source/sim_services/Executive/Executive_freeze_loop.cpp
index 19d5ef4bd..77ead7416 100644
--- a/trick_source/sim_services/Executive/Executive_freeze_loop.cpp
+++ b/trick_source/sim_services/Executive/Executive_freeze_loop.cpp
@@ -4,10 +4,13 @@
 
 #include "trick/Executive.hh"
 #include "trick/ExecutiveException.hh"
+#include "trick/CheckPointRestart.hh"
 #include "trick/exec_proto.h"
 #include "trick/message_proto.h"
 #include "trick/message_type.h"
 
+extern Trick::CheckPointRestart * the_cpr ;
+
 /**
 @details
 -# Set the mode to Freeze.  Requirement  [@ref r_exec_mode_2]
@@ -32,6 +35,10 @@ int Trick::Executive::freeze_loop() {
     }
 
     message_publish(MSG_INFO, "Freeze ON. Simulation time holding at %f seconds.\n" , get_sim_time()) ;
+    
+    if (!the_cpr->checkpoint_times.empty()) {
+    	the_cpr->write_checkpoint();
+    }
 
     while (mode == Freeze) {
 
diff --git a/trick_source/sim_services/VariableServer/Makefile_deps b/trick_source/sim_services/VariableServer/Makefile_deps
index 8d83bab4e..d585865ae 100644
--- a/trick_source/sim_services/VariableServer/Makefile_deps
+++ b/trick_source/sim_services/VariableServer/Makefile_deps
@@ -1,3 +1,6 @@
+
+object_${TRICK_HOST_CPU}/simModeCharString.o: simModeCharString.c \
+ ${TRICK_HOME}/include/trick/sim_mode.h 
 object_${TRICK_HOST_CPU}/VariableServerSessionThread_loop.o: VariableServerSessionThread_loop.cpp \
  ${TRICK_HOME}/include/trick/VariableServer.hh \
  ${TRICK_HOME}/include/trick/tc.h \
diff --git a/trick_source/sim_services/VariableServer/simModeCharString.c b/trick_source/sim_services/VariableServer/simModeCharString.c
new file mode 100644
index 000000000..0b193d1f9
--- /dev/null
+++ b/trick_source/sim_services/VariableServer/simModeCharString.c
@@ -0,0 +1,14 @@
+
+#include "trick/sim_mode.h"
+
+const char * simModeCharString(SIM_MODE mode) {
+    switch (mode)
+    {
+    case Initialization: return "Initialization";
+    case Run:            return "Run";
+    case Step:           return "Step";
+    case Freeze:         return "Freeze";
+    case ExitMode:       return "ExitMode";
+    default:             return "InvalidMode";
+    }
+}
\ No newline at end of file