Cewe Prometer 100, Руководство пользователя

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BGX501-943-R01 Prometer 100 User Manual Page 39 of 72
7.5 Digital inputs and outputs
The Prometer 100 has several inputs and outputs that can be configured to perform various tasks. Both inputs
and outputs are protected against overvoltages by varistors. They also have an isolated interface between the
electronics and the surroundings to ensure personal safety. For electrical data on the meter’s inputs and
outputs, see Appendix F: Connection and General Details (page 66).
7.5.1 Inputs
The inputs can be configured as follows:
•
Not used
The input is not used.
•
Finish historical period (To be verified that only ‘Finish Hist Period’ Input can be set to inverted
as in ConfigView S/W it allows none of the inputs to be set as inverted)
An incoming pulse will result in the present period ending and registers being copied to historical
registers. The meter registers pulses on positive or negative flanks, depending on if the input is set to
inverted or not. By setting limits for maximum and minimum pulse lengths, the meter can be limited as
to what it detects as a valid pulse. Pulses with lengths beyond the established limits are ignored. For a
pulse to finish historical period, it is also necessary that the Data communication be configured to allow
this. For more information, see the section Historical registers (pg.48).
Pulse
length
GND
VCC
Pulse length
(inverted input)
The figure shows pulse lengths when an input is inverted or non-inverted, respectively.
•
Pulse input
To register pulses from pulse-producing units such as energy meters, pulse inputs are used. Incoming
pulses are accumulated in registers called external registers. There is an external register connected to
each input on the meter. For external registers, a factor is configured by which the number of incoming
pulses is multiplied. Prefixes and the number of decimals can also be configured for the registers.
Moreover, the registers can be configured with descriptive texts.
•
Time synchronisation
When incoming pulses are received, the meter’s clock is synchronised at a specific interval For
available synchronisation intervals and more detailed information on time synchronisation, see the
section Meter clock (pg. 35).
•
Rate input
Up to three digital inputs can be configured to control the active rate. Each input will correspond to a bit
and the significance is also defined for the digital input. A high level on the input will signify that the bit is
“1” while a low level will signify “0”. How the digital input levels are mapped to rates is defined in the
Time of use panel (pg.48).
7.5.1.1 Registration of pulses
A pulse must be at least 20 ms (for 50 Hz) and 16 ms (for 60 Hz) long to be guaranteed of being detected by the
meter. The maximum pulse width that the meter can handle is 300 ms.