diff --git a/person_detection/base_camera.py b/person_detection/base_camera.py
index f36120a..e97dca2 100644
--- a/person_detection/base_camera.py
+++ b/person_detection/base_camera.py
@@ -7,13 +7,14 @@
 from multiprocessing import Process, Queue, Value, Array, Lock
 
 import roc
+import config
 
 
 class BaseCamera(object):
     process = {} # background process that reads frames from camera
     frame = {} # frame queue
     activity_counter = Value('i', 0)
-    cameras = Array('i', [0, 0, 0, 0])
+    cameras = Array('i', [0]*len(config.cameras))
     lock = Lock()
 
     def __init__(self, device, key, mbrlow, mbrhigh, devicegroup, noroc):
@@ -89,12 +90,12 @@
 
 
     def set_resolution_high(self):
-        for device in range(0, 4):
+        for device in range(0, len(config.cameras)):
             self.set_resolution(str(device), "high")
 
 
     def set_resolution_low(self):
-        for device in range(0, 4):
+        for device in range(0, len(config.cameras)):
             self.set_resolution(str(device), "low")
 
 
diff --git a/person_detection/config.py b/person_detection/config.py
index f31b769..ab510fa 100644
--- a/person_detection/config.py
+++ b/person_detection/config.py
@@ -3,4 +3,4 @@
 SPDX-License-Identifier: LicenseRef-ONF-Member-1.01
 """
 
-cameras = {"0": "Ain's desk", "1":"HungWei's desk", "2":"Shad's desk", "3":"Unknown"}
+cameras = {"0": "Ain's desk", "1":"HungWei's desk", "2":"Shad's desk"}