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Sub Meters
GE Multilin
6.3. Factory Settings
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Communication Protocol: Modbus – RTU
o
Baud Rate: 9600 bps
o
Data bits: 8
o
Stop bits: 1
o
Parity: Even
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Data type: 32-bit Float (Real) for all parameters unless otherwise specified.
o
Except for parameter:
Intr (Number of interruptions (Outages) in RMS parameter blocks) –
unsigned 32-bit integer data type.
RunSec (Run Seconds in Integrated block) – unsigned 32-bit integer data
type.
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Data Format: Direct reading from the meter, no scaling is required.
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Modbus Function code: 03 (Read)
6.4. Modbus Registers
•
Before integrating the Meters into your SCADA network, your SCADA software
must be configured for Modbus RTU communication, for the Address Blocks below,
by a qualified technician who understands your SCADA software
. Typically, the
Device Address, Block Start Address, Number of Registers (20 registers per EPM
2000 Data block of 10 x 32 bit values), must be configured to suit the meter.
Additionally, related SCADA settings for polling priority, logging and viewing the
Data must also be made. Refer your SCADA software instructions on how to do this.
•
Serial data from the Meter is available via the Modbus RTU protocol on the Serial
RS485 port. The Unit ID which is unique to each meter is programmed via the “Set-
Up” Menu thru the Front Panel keys.
•
All addresses are in Decimal. However, check your SCADA Program’s Modbus
driver specs such as an offset of 40,001. In this case of EPM 2000, Address 3000
must be treated as Modbus Register Address 43,001.
•
The EPM 2000 supports the transfer of whole block and also of individual Data
values (2 Registers are used for storing single Data value)
o
In transfer of whole block, it basically treats each block as an object with the
starting address (e.g. 3000) considered as the object name. This enables fast
block-transfers, since Energy Management usually requires a block of related
readings as of the same point of time. This method also eliminates time-skew
within readings of that Block.
o
In Transfer of individual Data values, it basically treats 2 registers as an
object with the starting address (e.g. 3900) considered as the object name.
This enables to transfer required Data values for Energy management.
•
Most of the Data are in 32bit format (IEEE Single Precision Float). 2 registers are
used for storing a single Data value. A float (or real) setting on your SCADA Driver
will usually suffice for automatic conversion. A few values are in Unsigned Long (32
bits).
•
Your SCADA software must support Register Blocks consisting of different Data
Types (Integers and Floats) to transfer of Whole Block.
•
Each Modbus register size is 16-bits. All EPM 2000 readings are 32 bits. Therefore,
each EPM 2000 reading occupies TWO consecutive Modbus Registers.
•
Most advanced SCADA packages will provide these capabilities.
