YOKOGAWA STARDOM FCN-500, Engineering Manual

Page: 219 / 226

<9. Advanced Engineering >
211
TI 34P02K35-02E May 31, 2017-00
9.2.6 Engineering Parameters
Engineering parameters of an NPAS POU are used to configure its operation, and
these parameter values can be assigned individually for each NPAS POU using
Logic Designer.
For convenience, engineering parameters of an NPAS POU are preset with default
values, which defines the default operation of an NPAS POU, unless the values are
otherwise modified during engineering.
Failure to modify engineering parameter values as required by a requirement
specification will result in an NPAS POU behaving differently from what is required.
To avoid such problems, always investigate what engineering parameters are
present in each NPAS POU used, what their default values are and whether any of
these default values need to be changed.
For reference, we describe some representative engineering parameters below. As
these parameters comprise only a subset, remember to check all engineering
parameters for each NPAS POU used.
• _SUM_SW (Totalization switch) Default: No totalization
This switch defines totalization for PV values. By default, no totalization is
performed.
• _CTL_DIR_SW (Control action direction switch) Default: Backward
This parameter specifies the direction of control for NPAS_PID, NPAS_PI_HLD,
NPAS_ONOFF, etc.
• _CTL_CYCLE (Control cycle) Default: auto-setting or general-setting
For details on control cycle, see Section 9.2.1, “Scan Cycle and Control Cycle.”
• _CLP_ACT_SW (Clamp activation switch) Default: ON
This switch defines the behavior when an NPAS POU in a cascade connection is
in a clamped state. For details on the operation of output clamp and the
_CLP_ACT_SW setting, read the NPAS POU online help documentation.
• _VN_ACT_SW (I/O compensation switch) Default: OFF
• _GAP_ACT_SW (Gap action switch) Default: OFF
• _DB_ACT_SW (Deadband action switch) Default: OFF