Ramp and Soak Function
The soak function is enabled by configuring alarm 1 to act as a dwell timer. If A1SF is set for TOON (time out on), the
alarm 1 relay will act as a timer contact, with the contact being open at power up and closing after the time set in ASP1
has elapsed. If A1SF is set for TOOF (time out off), the alarm 1 relay will perform the reverse action. If the heater (or
contactor coil) is wired in series through the alarm 1 relay and the out 1 relay, the controller will act as a guaranteed
soak controller.
In the example below, RAMP is set for 5.00°F/minute, A1SF=TOOF, and ASP1=40 (minutes). Power is applied at zero
time, and the process climbs from the ambient temperature of 50°F to the set point of 200°F over 30 minutes. The dwell
timer is activated upon reaching the set point and, after the soak time of 40 minutes, the alarm 1 relay will open,
switching off the output. The process temperature will then fall at an undetermined rate.
Dwell Function
The dwell function is enabled by configuring alarm 1 to act as a dwell timer. If A1SF is set to TOON (time out on), the
alarm 1 relay will operate as a timer contact with the contact being open on initial start up. The timer begins to count
down once the set point temperature has been reached. After the amount of time set in ASP1 has elapsed, the alarm 1
relay will close. This function can be used to operate an external device such as a siren or a light (for example) to alert
the operator when a minimum desired soak time has been reached.
In the example below, the ramp rate has been set to zero, A1SF=TOON, and ASP1=40 (minutes). Initial start up is at
zero time, and the process climbs to the 200°F set point at the maximum rate. Once the set point is reached, the dwell
timer begins to count. After 40 minutes, the alarm 1 relay closes. The controller will continue to act as a fixed set point
controller.
5–14 Re-ranging Linear Process Inputs
Select an appropriate input type (INPT). Define the range by adjusting LOSC and HISC. In the example below,
INPT=4–20 (mA), LOSC=0, HISC=100.0, and RESO=1DP. For a 4mA input, the process value will read 0 (LOSC), and
for a 20mA input, the process value will read 100.0 (HISC). For a 10mA input, the process value will read 37.5. If the
input signal is outside of the range defined by LOSC and HISC, an error message (LLEr or HLEr) will be shown in the
upper display.
21
40
minutes
200
∞
F
50
30
70
Time
(minutes)
Process value
Alarm 1 output
ON
OFF
Time (minutes)
40
minutes
Alarm 1 OFF
Alarm 1 ON
200 F
PV
∞
F
