Yaskawa APOGEE FLN P1 - Manual (Page 36)

10 APOGEE FLN P1 Communications
u Slope and Intercept Conversion
Several drive parameters are available for monitoring purposes. The available parameters include
FREQ OUTPUT (Point 3), SPEED (Point 5), CURRENT (Point 6), TORQUE (Point 7), POWER
(Point 8), DRIVE TEMP (Point 9), KWH (Point 10), and RUN TIME (Point 12). These points can
be unbundled for monitoring or used in various global control strategies .
u Drive Controlled Feedback
The most typical application is Supervisory Control. The sensor for the control variable (e.g.,
water temperature) is hard-wired to the drive and the control device (fan) is modulated using
the PI control loop built into the drive. The setpoint for the control variable (water temperature
set point) is unbundled and commanded by the field panel, based on the building control
strategy implemented in PPCL.
The point to unbundle and command for the set point is INPUT REF 1 (Point 60) when this
strategy is used. The control variable (e.g., water temperature) can be monitored by unbundling
PI FEEDBACK (Point 62). These points are provided in units of percent, where 0% and 100%
correspond to the range of the sensor being used to measure the control variable. These points
have default units in Hz. Unbundle these points with appropriate slopes and intercepts if other
units are required. The new intercept will be equal to the lowest value of the desired range.
The following formulas allow the user to define a new slope and intercept to convert the unit.
The following formulas allow the user to define a new slope and intercept to convert the unit.
(Desired Range) x (Slope of Existing Point)
(Range of Existing Point)
New Slope =
(60 - 0) Hz x (0.01)
(100 - 0)%
New Slope = = 0.006
n Conversion Example
The drive is controlling a fan, which in turn is controlling the water temperature from a cooling
tower. The temperature sensor has a range of -1 °C to +121 °C (30 °F to 250 °F). To unbundle
the set point (INPUT REF 1), for commanding in degrees Fahrenheit, where 0 to 60 Hz is equal
to -1 °C to +121 °C: New Intercept=30 (the temperature that corresponds to 0%).
(Desired Range) x (Slope of Existing Point)
(Range of Existing Point)
New Slope =
(250 - 30) °F x (0.1)
(100 - 0)%
New Slope = = 0.22
Note: 1. Desired Range=Range Maximum - Range Minimum
2. Range of Existing Point=Existing Range Maximum - Existing Range Minimum
10 APOGEE FLN P1 Communications
36 YASKAWA TOEP YAICOM 13 Metasys N2 & Apogee FLN P1 SI-J3 Installation & Technical Manual