Johnson Controls AIM-200 Technical Manual page 14

Table 1: Communications Loop Performance
Fault Condition
Single
Open on
Loop
Non-Redundant (2-Wire) Loop Operation
Trouble
(Note 1)
Redundant (4-Wire) Loop Operation
Trouble with
Alarm
Capability
Isolated Redundant (4-Wire) Loop Operation (Note 3)
Trouble with
Alarm
Capability
14 Addressable Intelligent Module—AIM -200 Addressable Intelligent Module
Single Loop has
Ground Been
on Loop Shorted
Trouble with Trouble
Alarm
Capability
(Note 2)
Trouble with Trouble
Alarm
Capability
Trouble with Trouble with
Alarm Alarm
Capability Capability
Notes:
1. Trouble indicates that a trouble signal will be generated at the control
panel under the abnormal condition.
2. Alarm capability indicates whether or not an alarm signal can be
transmitted to the control panel during the abnormal condition.
3. Isolated redundant loop operation is a method of protecting, or
isolating, entire physical zones of devices on the communications loop
from faults that occur within other areas of the loop.
Loop Loop
Shorted Shorted
and and
Opened Grounded
Trouble Trouble
Trouble Trouble
Trouble Trouble with
Alarm
Capability
Loop Communication
Opened Loss with
and Control Panel
Grounded
Trouble Trouble
Trouble with Trouble
Alarm
Capability
Trouble with Trouble
Alarm
Capability