Operating Instructions

Chapter 9 – SED2 Communications
Siemens Building Technologies, Inc. 87
Chapter 9 — SED2 Communications
Overview
The SED2 drives are a family of inverters that are built, sold, and serviced by Siemens
Building Technologies, Inc.- Adjustable Frequency Drives Group (SBT-Drives). Siemens
Building Technologies has a Protocol 1 (P1) communication driver, FLN connection, and
point database that is built into their drives and allows them to coexist on an APOGEE
network with other floor level network (FLN) devices.
The Siemens Building Technologies representative is responsible for proper configuration of
the drive for its primary application as well as field panel programming, to make use of the
drive functionality in the building automation system.
Chapter 9 describes how to access the SED2 from a field panel and how to use a SED2 as
part of a larger control scheme.
Using the Serial Interface
The serial interface uses an RS-485 two-wire connection. Up to 30 drives can connect on a
single RS-485 link, and drives can be addressed individually or with a broadcast message.
This configuration requires a separate master controller and the drives act as slaves.
Using a serial interface has several advantages:
• Wiring can be greatly reduced.
• Control functions can be changed without rewiring.
• Parameters can be set up and changed via the interface.
• Performance can be continuously monitored and controlled.
Working with Serial Communications
Introduction
This section describes the hardware aspects of the serial communications that are used with
the SED2. It does not discuss or detail the software protocols that are used or how to debug
the software. Software protocols are discussed later in this section.