CHAPTER 4: COMMUNICATIONS
MODBUS MEMORY MAP
EPM 4
5
00 SUB METER – INSTRUCTION MANUAL
4–9
4.3
Modbus Memory Map
4.3.1
Memory Map
The Modbus memory map is shown below.
Table 4–1: Modbus Memory Map (Sheet 1 of 15)
Hex
Addr
Addr
Description
R/W
Units
Notes
Fixed Value Registers (Read Only)
0000
+
0000
Meter Serial Number
R
hex digits
0002
+
0002
Meter Serial Number Extension
R
hex digits
Returns same value as address 0000
0004
+
0004
Meter Version Number
R
hex digits
0006
+
0006
Meter Version Number Extension
R
hex digits
Returns same value as address 0000
0008
0008
Meter Modbus Address
R
---
8-bit Modbus Address in LSB
Setup Information
0009
0009
Baud Rate
R
000C
0012
Meter Status
R
---
Always 1 for Modbus.
000D
0013
Meter Ready
R
---
Always 1 for Modbus.
000E
0014
Number of Meters Configured
R
---
Always 1 for EPM4
5
00
000F
0015
Number of Real-Time Points Configured
R
0010
0016
Number of Interval Points Configured
R
Returns 0 if intervals are disabled
0011
0017
Number of Max/Min Points Configured
R
Always returns 0
0012
0018
Maximum Number of Intervals That Can Be Recorded
R
Dependent upon the number of parameters optioned
and the number of meters returned in address 0015
0013
0019
Number of slots configured for Scan Transponder
R
0014
0020
Current slot being read in Scan Transponder
W
Interval Setup
0031
0049
Store Interval Length
R
minutes
Interval length in minutes must be evenly divisible into 60
(1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60)
Read Clock
0032
0050
Internal Time - Hours/Minutes
R
hours/minutes
16-bit, Hours: 0-23 (bitmask = FF00)
Minutes: 0-59 (bitmask = 00FF
0033
0051
Internal Time - Seconds
R
seconds
0034
0052
Internal Date - Month/Day
R
month/day
0035
0053
Interval Date - Year
R
year
0036
0054
Internal Time - Hours/Minutes
W
hours/minutes
16-bit, Hours: 0-23 (bitmask = FF00)
Minutes: 0-59 (bitmask = 00FF
0037
0055
Internal Time - Seconds
W
month/day
0038
0056
Internal Date - Month/Day
W
Year
16-bit Unsigned Integer
0039
0057
Interval Date - Year
W
16-bit Unsigned Integer