Operating Instructions

Chapter 9 – SED2 Communications
Siemens Building Technologies, Inc. 91
Strategies for FLN (P1)
Monitoring – Several SED2 parameters are available for monitoring purposes. These
include both binary and analog data.
• FREQ OUTPUT (Point 3); the output frequency of the SED2 in Hz
• SPEED (Point 5); the SED2 output speed in RPM
• CURRENT (Point 6); the output current of the SED2 in amps
• TORQUE (Point 7); torque in percentage of nominal torque
• DC BUS VOLTS (Point 13); the DC bus voltage of the SED2
• RATED POWER (Point 16); the motors rated power
• OUTPUT VOLTS (Point 17); the output voltage applied to the motor
• ENABLED (Point 27); the SED2 is ready to run or disabled
• READY TO RUN (Point 28); the ready status of the SED2
• FREQ REFERENCE (Point 51); percent of the SED2 speed setting
• LAST FAULT (Point 90); last fault code that occurred
• 1st, 2nd & 3rd FAULT (Points 91 to 93); the three faults that occurred before the last
fault
In addition to the above, ADDESS (Point 1), APPLICATION (Point 2), TIME (Point 20),
DAYNIGHT (Point 29), and OVRD and ERROR STATUS (Point 99) are supported by and
comply with FLN requirements.
Unbundle these points for monitoring or use them in various control strategies. For a detailed
description of these drive parameters, see other sections in this User Manual.
Additional display points on the SED2 drive that may be of use:
• INVERTER VER (Point 83); the SED2 firmware version number
• DRIVEMODEL (Point 84); the STB drive model number
Supervisory Control – This is the most typical application. The sensor for the control
variable (water temperature) is hard-wired to the SED2 and the built-in SED2 control loop (PI
loop macro must be enabled during drive setup) modulates the control device (fan). Change
Point 64 (Parameter P2200) to 1 to enable PID control. When using the SED2 PID mode, you
will need to program other parameters depending on the application circumstances. These
parameters include PID system gain, integral, and differential adjustment to stabilize the PID
control system for the application. Set these parameters during SED2 commissioning. For
examples of the PID loop macro, see other sections in this User Manual.