Rockwell Automation 1756-OF8I ControlLogix Eight-channel Isolated Analog I/O Modules - Manual (Page 53)

Rockwell Automation Publication 1756-UM540A-EN-P - May 2014 53
1756-IF8I Isolated Analog Input Module Chapter 3
Process Alarms
Process alarms alert you when the module has exceeded configured high or low
limits for each channel. These are set at four, user-configurable, alarm
trigger points:
• High high
• High
• Low
• Low low
You can enable or disable Process Alarms individually via the Output tags for
each channel. When a module is added to your Logix Designer application
project and tags are created, the Alarms are disabled by default.
Each individual Process Alarm enable tag, that is, O.Ch[x].LLAlarmEn,
O.Ch[x].LAlarmEn, O.Ch[x].HAlarmEn and O.Ch[x].HHAlarmEn, is disabled
when the module is created. You must enable the tags in the Output Data to
allow the individual alarm to trigger.
If a Process Alarm's enable bit is not set, the corresponding Input Process Alarm
never triggers. To see where to set the Process Alarms, see
page 131 .
You can latch process alarms. The alarm remains on, even if the condition causing
it to occur disappears, until the alarm is unlatched.
IMPORTANT You must manually unlatch the alarm. You can unlatch the alarm, by using one
of the following methods:
• While the project is online, click the Alarm Configuration tab on the
Module. Then click Unlatch to unlatch a specific alarm or Unlatch All to
unlatch all alarms.
• Change the module output tag for the alarm that you want to unlatch. For
example, the Ch[x].LLAlarmUnlatch tag to unlatch a Low Low Alarm.
For more information on module tags, see Appendix A, Isolated Analog I/O
Module Tag Definitions on page 173 .
• Use a CIP Generic message.
For more information how to use a CIP Generic message, see Rockwell
Automation Knowledgebase article #63046, How to Reset Latched Status
of an Analog Module. You can access the article at:
https://rockwellautomation.custhelp.com/