User's Manual

C1697M-B (11/08) 71
Understanding the Threshold Percent
The Threshold Percent allows you to specify the number of blocks in a motion zone that must detect motion before a motion event can be
initiated.
Scenario 1: Motion Zone = 100 Blocks
For example, if the motion zone has 100 blocks (maximum setting), you can set the Threshold Percent option to 2 (minimum setting). In this case,
the number of detection blocks in the motion zone can be as few as 2 (refer to Figure 80). You can adjust the threshold blocks from 2–100 blocks.
These values are derived as follows:
Number of Detection Blocks = (Zone Blocks x n%)/100 or 100 x 2/100 = 2
Figure 80. Motion Zone and Threshold Percent: Example 1
NOTE: Threshold Blocks cannot be set to a value less than 2. If you attempt to do so, the remote client will automatically readjust the value to 2.
Scenario 2: Motion Zone = 50 Blocks
If the motion zone has 50 blocks and you attempt to set the Threshold Percent option to 2 percent, the remote client automatically readjusts this
value to 4 percent (refer to Figure 81 on page 71).
Number of Detection Blocks = (Zone Blocks x n%)/100 or 50 x 4/100 = 2
Figure 81. Motion Zone and Threshold Percent: Example 2
Scenario 3: Small Motion Region = 16 Blocks; Large Motion Region = 56 Blocks
If multiple regions are defined in a motion zone, the DVR5100 Remote Client:
• Adds the blocks from each region to arrive at total blocks for the motion zone.
• Bases the threshold calculation on the total blocks.
For example, in Figure 82 on page 72, there are two regions: a larger region (56 blocks) and a smaller region (16 blocks) totaling 72 total blocks
assigned to the motion zone. The Threshold Percent is set to 28. In this case, 20 blocks (72 blocks x 28% = 20) must detect motion before a
motion event is triggered.