GE Industrial Solutions EPM1500 Single Point Submetering System - Manual (Page 35)

CHAPTER 4: COMMUNICATIONS
EPM 1500 SUB-METER– INSTRUCTION MANUAL 4–3
• Real Power in kW
• Reactive Power in kvar
• Apparent Power in kVA
• Power Factor
Data is logged per the configurable time interval value. The default log interval is 15
minutes.
The Modbus master can request stored interval data by writing the interval date and time
to the appropriate registers and by setting the data status register to 1. Upon the data
ready flag (address 67) being written to 1, the interval data registers (addresses 100 to 107)
are simultaneously updated with the appropriate values for the requested interval. The
data ready flag returns a 0 for “data is ready”, or “2” for “invalid time interval requested.”
The EPM 1500 also provides registers that constantly hold the oldest stored-interval
(addresses 58 to 60) and most recent stored-interval time and date stamps (addresses 61
to 63).
4.1.6 Instantaneous Data Items
The EPM 1500 provides registers for per-phase instantaneous values (see below).
Instantaneous register values are updated once per second.
• Frequency
• Total Harmonic Distortion (% for volts)
• Voltage
• Current
• Real Power in kW
• Reactive Power in kvar
• Apparent Power in kVA
The EPM 1500 provides one-second updated inputs, including the following 3-phase-
totaled values per 3-phase-meter:
• Energy: kWh and kvarh
• Power: kW, kvar, and kVA
• Power Factor
4.1.7 32-bit Long and Float Data Formats
The EPM 1500 supports standard format for 32-bit Long (signed or unsigned). The first of
the two 16-bit Modbus register set contains the HIGH order 16 bits of the 32-bit Long data.
The second of the two 16-bit Modbus register set contains the LOW order 16 bits of the 32-
bit Long data.
The EPM 1500 supports Intel 32 bit (IEEE) FLOAT format. That means, unlike the standard
Long format, the first of the two 16-bit Modbus register set contains the LOW order 16 bits
of the 32-bit Float data. The second of the two 16-bit Modbus register set contains the
HIGH order 16 bits of the 32-bit Float data.