Watlow Series 920 Microprocessor-Based Ramping Control - Manual (Page 56)

The Operating Band
Now we need to set the alarm limits. In doing so, you’ll define an “operating
band” where you want system temperature (or your controlled variable) to be .
“OK” and alarm-free.
By selecting an alarm type (ALTYP), and then the alarm limits (AXL, AXH), you
define the Operating Band. The extreme limits of the Operating Band are
defined by the 920s high and low ranges, see the table below.
The following limits are enabled when RAL and RAH are at their maximum
default values. If RAL or RAH are changed, the corresponding process alarm
value will also change to the RAL/RAH value. If the input type is 0-5VDC or
4-20mA, the process alarm value will change to their default value.
If RAL or RAH are changed, the deviation alarm value will change to its default
value.
Table 11 -
Operating Band
Limits and Ranges.
56 WATLOW Series 920 User’s Manual