Publication 900-UM007D-EN-E - January 2011
4-8
Parameter Adjustments & Application Considerations
Alarm Functions/
Parameters
Alarm Hysteresis
You can configure/program how much deviation (hysteresis) is allowed from
the alarm value before the alarm comes on and reset.
The hysteresis of alarm outputs when alarms are switched ON/OFF can be
set as follows:
Figure 4.15 — Hysteresis of Alarm Outputs
Alarm hysteresis is independently set for each alarm output in the Alarm
Hysteresis 1…3 parameters (Advanced Setting function group).
Note:
The default is 0.2 (°C or °F depending on your units selection) for
temperature inputs and 0.02% of full scale (FS) for analog inputs.
Standby Alarm Sequence
Standby alarm sequence is a function which allows you to configure the alarm
outputs to be temporarily disabled until
after
the
first
alarm condition occurs.
From then on, the alarm output is active for all future alarm conditions.
For example, in a standard heating application, if you used the standard low
alarm configuration, the alarm would be active as soon as you switch the
controller ON. However, with standby sequence, the alarm output is disabled
during the first warm-up, and the temperature has to rise above the alarm set
point before the alarm can become active. Then, if the temperature falls below
the alarm set point, the output is active.
Restart
As mentioned above, the standby sequence is canceled
after
the
first
real
alarm clears. If desired, it can be restarted later by the Standby Sequence
parameter (Advanced Setting function group). For details, refer to page 5-72,
Standby Sequence Reset Method
.
ON
OFF
ON
OFF
Normal
Operating
Area
SP
Normal
Operating
Area
SP
Alarm Value
Alarm Value
Alarm Hysteresis
Alarm Hysteresis
Upper-Limit
Alarm
Lower-Limit
Alarm
Summary of Contents for Allen-Bradley 900-TC16
Page 1: ...USER MANUAL Bulletin 900 TC8 900 TC16 900 TC32 Series B Temperature Controllers...
Page 2: ...2...
Page 72: ...Publication 900 UM007D EN E January 2011 3 2 Configuration Basic Operation Figure 3 3 900 TC32...
Page 136: ...Publication 900 UM007D EN E January 2011 3 66 Configuration Basic Operation Notes...
Page 340: ...Publication 900 UM007D EN E January 2011 5 112 Parameter Functions Definitions Notes...
Page 350: ...Publication 900 UM007D EN E January 2011 6 10 Troubleshooting Error Indication Notes...
Page 406: ...Publication 900 UM007D EN E January 2011 D 8 Glossary Notes...