Basler Electric DECS-400 - Manual (Page 18)

6 9369700990 Rev R
Metering
Two programmable, 4 to 20 mAdc, analog meter drivers are provided. The meter side is isolated from
DECS-400 circuitry. Either driver can be programmed to meter a broad range of generator and system
parameters.
Sequence of Events Recording
An integrated sequence of events recorder (SER) can be used to reconstruct the exact time of an event
or disturbance. The DECS-400 monitors its contact inputs and outputs for changes of state, system
operating changes, and alarm conditions. If any of these events occurs, the DECS-400 logs that event
with a date and time stamp. The resulting event record allows the user to analyze a chain of events with
accurate information regarding the sequence in which they occurred. Up to 127 events can be stored in
DECS-400 volatile memory and those events are retrievable through BESTCOMS software.
Oscillography
The data recording feature can record up to six oscillographic records and store them in volatile memory.
Up to six variables can be selected for monitoring. These variables include generator voltage, generator
current (single-phase), frequency, kW, power factor, field voltage, and field current. Oscillographic records
can be triggered through BESTCOMS or by a logic trigger or level trigger.
During commissioning, BESTCOMS can be used to trigger and save a record of a voltage step response.
At the completion of commissioning, a logic trigger or level trigger can be used to activate the data
recorder to capture the occurrence for review at a later time. DECS-400 alarms can also be used to start
the data recorder. When an alarm condition occurs, an oscillographic record can be stored. A level trigger
will initiate a record to be saved when a variable (such as field current) exceeds a predetermined setting.
Oscillographic records are recorded in accordance with the IEEE Standard Common Format for Transient
Data Exchange (COMTRADE) or log file format. Basler Electric provides BESTwave
™, a COMTRADE
viewer that enables viewing of oscillography records saved by the DECS-400.
Real-Time Monitoring
Real-time monitoring is possible for any of the parameters available for oscillography. The HMI real-time
monitoring screen will display up to two parameters simultaneously. This data can be stored in a file for
later reference.
Internal Testing Provisions
Using BESTCOMS, the user can configure and run both frequency and step response tests to facilitate
commissioning or demonstrate system performance. The frequency response test has a frequency range
of 0.1 to 10 hertz, and gain/phase information is generated in the form of a Bode plot. The DECS-400
also allows injection of test signals at various points in the PSS/voltage regulation loop for a high level of
testing flexibility.
Communication
The DECS-400 is supplied with BESTCOMS software which makes DECS-400 programming and
customization fast and easy. BESTCOMS includes a PID selection utility that provides a user-friendly
format for selecting stability settings. BESTCOMS has monitoring screens for viewing all settings,
metering screens for viewing all machine parameters, and control screens for remote control of the
excitation system. A file converter within BESTCOMS enables conversion of DECS-300 settings files for
use with the DECS-400.
An RS-485 port on the rear panel supports Modbus
™ (floating point) communication protocol. Modbus™ is
an open protocol, with all registers and operating instructions available in this instruction manual. This
makes it simple for the user to develop custom communication software.
An Ethernet port on the rear panel enables communication with the DECS-400 over a TCP/IP network.
Ethernet support in the DECS-400 enables remote access to DECS-400 settings and data through
Modbus TCP or BESTCOMS. DECS-400 time synchronization with a network time server is also
possible.
General Information DECS-400