Rockwell Automation FactoryTalk View Site Edition Users Guide User Manual
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The choices you make will depend on factors such as the design of your application, the
processes you need to monitor for alarms, the types of devices used in the application, and
whether you want to build alarm detection into those devices.
Advantages in using FactoryTalk Alarms and Events services
There are advantages in using FactoryTalk Alarms and Events services for alarm
monitoring and control, when compared with using traditional, HMI tag alarms.
FactoryTalk Alarms and Events offers a single, integrated set of alarm information,
distributed through supporting alarm servers. This means that all clients in a FactoryTalk
system can receive a consistent view of device-based and tag-based alarm activity.
FactoryTalk Alarms and Events services are also integrated with FactoryTalk Security
services. This means you can set up FactoryTalk system users and computers with
different levels of access to alarm sources and data.
Choosing FactoryTalk device-based alarms
FactoryTalk device-based alarms are set up by programming alarm instructions directly
into Logix5000 controllers that support built-in alarm detection.
Following are some reasons why you might choose device-based alarms, when compared
with using HMI tag alarms.
Using device-based alarms
Using HMI tag alarms
Alarm detection instructions are
programmed once, in the controller.
Alarm detection is programmed in the
controller, and in FactoryTalk View SE.
To set up HMI tag alarms, first you must
create the HMI tags, which are mapped to
tags in the controller. Then, in a separate
step, you must add alarm conditions to the
HMI tags you want to monitor.
This duplication of programming effort can
lead to errors.
Alarms are processed once, in the
controller. Data polling is eliminated.
This reduces network overhead and speeds
up alarm detection.
Alarms are processed in the controller, and
in FactoryTalk View SE.
To monitor alarms, the HMI software polls
tags in the controller. If alarms are detected,
the HMI software notifies clients.
Alarm states are managed, processed, and
preserved in the controller.
Alarm states are stored on the HMI server
computer. If the computer is disconnected
from the network, or if the HMI server fails
or is restarted, alarm states might be lost.