diff --git a/eth_cmd_test.py b/eth_cmd_test.py
index f380173..3b74d33 100644
--- a/eth_cmd_test.py
+++ b/eth_cmd_test.py
@@ -93,6 +93,8 @@ def read_cmd(input, socket):
 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 
 def signal_handler(sig, frame):
+    ld_cmd["data_f64"] = 0.0
+    send_cmd(ld_cmd, s)
     send_cmd(tec_power_down, s)
     s.close()
     exit()