Watlow Series 922 - Manual (Page 65)

How To Use The Alarms, Chapter 7
65
WATLOW Series 922 User's Manual
Alarms
Temp
SP1
Actual
0
°
C
Time
New SP1
AH 2
AH 1
AL 1
AL 2
A1H
A1L
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 922's high and low ranges, RXL and RXH.
Alarm Limits
You can set up alarm bands with the two available alarms. Each of the two
alarms has a high and a low limit point, indicated by the "L" or "H" designation.
You specify in the Operating Data where you want A1L, A1H, A2L, and A2H.
These limit points are themselves restricted by the controller's high and low
range Operating Parameters, RXH and RXL. In other words, you can't set an
alarm limit beyond the range limits you enter into the microprocessor.
Figure 36 -
Alarm Limits for
Alarms 1 and 2 with
"Process" Type
Alarm (ALTYP1=P,
ALTYP2=P)
NOTE: Only Chan-
nel 1 is shown here.