Direct/Reverse Operation - Omron E5EK DEVICENET User Manual

CHAPTER 3 BASIC OPERATION
J Direct/reverse
operation
J Control period
3--8
• "Direct operation" (or normal operation) refers to control where the
manipulated variable is increased according to the increase in the
process value. Alternatively, "reverse operation" refers to control
where the manipulated variable is decreased according to the decrease
in the process 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 sys-
tem. Alternatively, this becomes "direct operation" in a cooling control
system.
• Direct/reverse operation is set in the [
tion" 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 opera-