Rockwell Automation 900-TC32 Digital Temperature Controllers, Series B - Manual (Page 88)

Publication 900-UM007D-EN-E - January 2011
3-18 Configuration & Basic Operation
Figure 3.21 — Direct/Reverse Operation
For example, when the process value (PV) temperature is lower than the set
point (SP) temperature in a heating control system, the manipulated variable
(OUT1) increases (ON) by the difference between the PV and SP values.
Accordingly, this becomes reverse operation in a heating control system, or
alternatively, direct operation in a cooling control system.
Direct/reverse operation is set in the Direct/Reverse Operation parameter
(Initial Setting function group).
Note: The Direct/Reverse Operation parameter default is reverse operation.
EXAMPLE
Operation Procedure
In this example, the Input Type, Temperature Unit, Direct/Reverse Operation,
and Control Period (HEAT) parameters will be monitored.
The setup of parameters is as follows:
Input Type =
5: K thermocouple
Temperature Unit =
c: °C
Direct/Reverse Operation =
or-r: reverse operation
Control Period (HEAT) = 20 seconds
1. Press the
O
key for at least 3 seconds to move from the Operation
function group to the Initial Setting function group.
High temperature
Manipulated variable (MV)
Direct operation
Low temperature
Set value (SP)
High temperature
Manipulated variable (MV)
Reverse operation
Low temperature Set value (SP)
100%
0%
100%
0%