Omron E5EK - MANUAL 2 User Manual page 35

CHAPTER 3 BASIC OPERATION
+ Direct/reverse
operation
+ Control period
3–8
Direct operation" (or normal operation) refers to control where the
manipulated variable is increased according to the increase in the pro
cess value. Alternatively, reverse operation" refers to control where the
manipulated variable is decreased according to the decrease in the pro
cess value.
For example, when the process value (PV), is lower than the set point
(SP), in a heating control system, the manipulated variable increases by
the difference between the PV and SP values.
Accordingly, this becomes reverse operation" in a heating control system.
Alternatively, this becomes direct operation" in a cooling control system.
Direct/reverse operation is set in the [
parameter (setup mode).
When the output unit is pulse output such as relay output, set the pulse
output cycle (control period). Though a shorter pulse period provides
better control performance, the control period should be set taking the
life expectancy of the output unit into consideration when the output
unit is relay. It is recommended that the control period be set to longer
than 20 seconds.
The control period is set in the control period (heat)" parameter (level
1 mode). Factory setting is 20:20 seconds."
The control period (cool)" output function is not allocated. So, the
control period (cool)" parameter cannot be set.
]direct/reverse operation"