diff --git a/apsct_lib.py b/apsct_lib.py
index 5ff0196084be5c168de040942a41528d82440f4d..886a37a01ba5d9ca8cd48d1ccb77719e5b3f2799 100644
--- a/apsct_lib.py
+++ b/apsct_lib.py
@@ -246,7 +246,6 @@ class PllClass:
         #
         # Read all registers on the PLL and print on screen
         #
-        self.dev_i2c_pll.write_bytes(0x07, 0x00)
         bytes_to_read = 12
         ret_value = self.read_byte_pll(0, nof_bytes=bytes_to_read)
         for cnt in range(bytes_to_read):
@@ -258,19 +257,21 @@ class PllClass:
         #
         # Read lock status
         #
-        ret_value = self.read_byte_pll(0x00, nof_bytes=1)
-        status_pll = int(ret_value, 2)
-        if status_pll == 0x04:
+        if (self.frequency == '200MHz'):
+            i2_c_io_device = I2C(0x20, BUSNR=I2CBUSNR)
+        else:
+            i2_c_io_device = I2C(0x21, BUSNR=I2CBUSNR)
+        i2_c_io_device.write_bytes(0x06, 0x2C)  # '0' is output
+        i2_c_io_device.write_bytes(0x07, 0x00)  # '0' is output
+        ack, ret_value = i2_c_io_device_b.read_bytes(0x00, 1)
+        status_pll = ret_value & 0x02
+        if status_pll == 0x02:
             self.lock = True
             stri = f"PLL {self.frequency} is in lock"
-        elif (status_pll & 0x10) > 0:
-            self.lock = False
-            stri = f"PLL {self.frequency} Not Locked --> No 10 MHz ref"
         else:
             self.lock = False
-            stri = f"PLL {self.frequency} Not locked --> PLL Error"
-        if print_on:
-            print(stri)
+            stri = f"PLL {self.frequency} is not locked"
+        print(stri)
         return self.lock
 
     def read_lol(self):