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6.6 Calibration
Led
A red led is located on the instrument front panel pulsing with a 1000 pulse/kWh (or kvarh) and 50 ms
pulse duration. The pulses number is referred to the instrument end of range without the CT and VT scale
factors.
6.7 Digital
Outputs
The two outputs are (mostly) used as pulse output on active/reactive power or as output for the internal
triggers. In other configurations, where the instruments is controlled – by a PC or PLC - through the RS485
port, the outputs can be used for signaling remote activation/deactivation.
6.8 Pulse
Output
The two outputs, if in association with pulse, can be referred to one of the 8 power value available on a 4
quadrant system.
The output pulse can be freely programmed both on frequency and duration and referred to the instrument
Full Scale or to the measuring cell (with CT and PT) Full Scale.
It is possible to program the output value either according to pulse number and pulse weight
The two outputs are factory programmed one proportional to the active energy while the other to the
reactive energy, the output frequency is 1000 pulses per kWh (or kvarh) and 50 ms pulse time.
The pulses number is referred to the instrument Full Scale without the CT and TV scale factors.
6.9 Alarms
X3M is triggered and programmed by switchboard and/or Holding registers with MODBUS protocol.
The advanced functions of the Energy Brain configuration software allow to customize each of the two
alarms on any available parameter either as a minimum or max alarm. Two different thresholds of the
same measurement can be programmed.
Minimum value and maximum value special alarms on voltage are available that can be applied on any of
the three phases, one maximum value alarm on current that can be applied on any of the three phases
and an unbalanced alarm on any of the three current phases.
A further flexibility in customization is provided by the possibility to program the alarm management
through:
•
Delay time (between 1 and 59 sec.) that is activation delay. Example: avoid alarms due to short
signal peaks.
•
Hysteresis, that is the cycle between the alarm activation value and the alarm deactivation value. It
is an extremely useful function to avoid ringing and false triggering. Example: Current alarm set on
100A Max with 5% Hysteresis. The alarm is activated at 100 A and is deactivated at 95 A. The two
alarms can be associated singularly to:
•
Output relays. In this case the output relays are activated by the exceeded threshold
•
RS485 data line. The relays are disabled and the alarm consolidation are disabled and the alarm
condition is available as information on information on RS485. data line.
6.10 Communication
The device can be connected to a PC through an optional RS485 or RS232 port using the MODBUS
communication protocol (MODBUS, developed by AEG-MODICON, is a standard in the PLC industry and
widely utilized by SCADA systems for industrial plants management).
Data read by the device can be read as the content of numeric registers, in the standard
mantissa/exponent floating point IEEE format.
The communication port can be operated at any speed between 2400 bps through 38400 bps without wait
states between 2 requests with a limitation on the number of registers equal to 124 registers (62
parameters)
When using the optional RS485 port, the connection uses a standard telephone pair without need of signal
regeneration/amplification for distances up to 1,000 m. Up to 128 devices can be connected on the same
network branch. Using line amplifiers, it is possible to connect up to 247 instruments or 1,000 m network
segments.
