User guide

MR-2100/2200 Programming Manual
3
Network Verify
Network Verify is the process by which the master panel queries the rest of the network to
determine on-line status. Each panel will respond to the network verify request. The user can also
request a Network Verify at any time from any panel in the network.
Network Communications
Information is sent across the network in frames. In addition to the operator generated frames
described above, alarm, supervisory, and trouble frames are sent across the network
whenever a device or panel indicates a problem. There are two types of frames: specific and
broadcast. Specific frames are sent from one unit to another. Broadcast frames are sent from one
unit to all others.
Specific Frames
Specific frames deal with information generated at one panel and required at another. This type of
frame is passed from panel to panel until it reaches its destination. Each panel has a list as to
which port to send frames from to reach all other panels through the fewest number of panels.
Since networks generally have all communications links running at the same baud rate, this is
generally the shortest time as well.
If there is a break in the communications (see Figure 2), the panel that cannot pass the message
on sends it back the way it came. This causes the frame to go the long way around the network. If
there are two breaks in the network loop, the frame is again reversed at the second break. When
the originating panel receives it after the second turn around, the originating panel realizes there is
a major fault in the network and considers the frame to be orphaned and destroys it. This
generates a Network Reboot Required trouble. This is passed on to all other panels (or at least as
many as can be reached). The reason the orphan frame is destroyed is to prevent unexpected
operation when the network is finally repaired, such as a panel starts ringing its bells because of
an alarm from the previous day.
Figure 2: Single Network Break
M R 2200
ID # 1
C O M 2 C O M 1
MR2900
ID # 2
C O M 2 C O M 1
MR2944
ID # 3
C O M 2 C O M 1
M R 2200
ID # 5
MR2944
ID # 4
C O M 1 C O M 2C O M 1 C O M 2