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Powercom3
Undercover Modbus Unit
User Manual
Revision 04
Camax UK Limited
Unit 8 Jubilee Court
Copgrove
Harrogate
North Yorkshire
Telephone: 01423 340 000
Website: www.camax.co.uk
E-Mail: sales@camax.co.uk
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Table of Contents
1. Introduction ...................................................................................................................................... 4
2. Configuration ................................................................................................................................... 4
2.1. DIP Switch .................................................................................................................................... 4
2.1.1 Address ........................................................................................................................................ 4
2.1.2 Modbus disable ........................................................................................................................... 5
2.1.3 Meter type ................................................................................................................................... 5
3. Device modes ................................................................................................................................... 5
3.1 Program mode ................................................................................................................................ 5
3.1.1 Command set ............................................................................................................................... 5
3.1.1.1 METER command ................................................................................................................... 6
3.1.1.2 RS232 command ...................................................................................................................... 6
3.1.1.3 RS485 command ...................................................................................................................... 6
3.1.1.4 SERNO command .................................................................................................................... 6
3.1.1.5 VERSION command ................................................................................................................ 6
3.2 Non addressed transparent mode ................................................................................................... 6
3.3 Addressed transparent mode .......................................................................................................... 6
Annexure A: Register Map................................................................................................................... 8
Annexure B: Status indication ........................................................................................................... 13
Annexure C: Pinouts .......................................................................................................................... 15
Annexure D: USB Adapter ................................................................................................................ 16
Annexure E: Python Code Examples ................................................................................................. 17
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ON
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1.
Introduction
The Modbus Unit has been specifically designed to work with Elster's A1140 and A1700
energy meters and fits under the terminal cover. The power supply of the unit is taken
directly from a A1140 and from an additional power adapter when used with the A1700.
The unit can be configured in one of three modes; modbus mode, transparent mode with
addressing and transparent mode without addressing.
2.
Configuration
The configuration is done via the on-board DIP switch and terminal commands entered via
the RS232 port.
2.1.
DIP Switch
The 8-way switch is divided into 3 groups as follows:
Address
Modbus disabled
Meter type
2.1.1
Address
The address field is bit mapped and has a range of 1 to 31. Switching a bit position to the
on position will add the binary value to the address, e.g.
Address = 1
Address = 2
Address = 1 + 2 = 3
Address = 4
Calculate the address as follows:
Address = sum of value of bit positions set to on.
Each bit position has a value of 2
((bit position)
– 1), so if position 1 and 3 is on the address will
be:
Address = 20 + 22 = 5
ON
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ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
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ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
2.1.2
Modbus disable
Set this position to on to disable the modbus functionality. This will result in the unit to
disable any meter protocol and enter the transparent mode.
Modbus enabled
Modbus disabled
2.1.3
Meter type
This selects the meter type, valid settings are:
A1140
A1700
3.
Device modes
3.1 Program mode
Program mode is entered when all dip switch positions are set to the on position.
The program mode command interpreter will listen on the RS232 port (RJ12) at 9600
baud, no parity and one stop bit.
A USB dongle available from Camax UK may be used to gain access to the RS232 port.
3.1.1 Command set
Typing help at the command line displays the available commands, these are: METER,
RS232 and RS485.
ON
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ON
1 2 3 4 5 6 7 8
ON
1 2 3 4 5 6 7 8
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3.1.1.1 METER command
Sets the outstation and password via parameters:
--addr=<outstation>
--pass=<oldpass,newpass>
e.g.
meter --addr=2
meter --pass=FEDC0003,12345678
3.1.1.2
RS232 command
Sets the parameters for the RS232 port (RJ12) via parameters:
--baud=<baudrate>
--parity=<0=none | 1=odd | 2=even>
--stopbits=<1 | 2>
--read-timeout=<milliseconds>
3.1.1.3
RS485 command
Sets the parameters for the RS485 port (RJ45) via parameters:
--baud=<baudrate>
--parity=<0=none | 1=odd | 2=even>
--stopbits=<1 | 2>
--read-timeout=<milliseconds>
3.1.1.4
SERNO command
Display the serial number
3.1.1.5
VERSION command
Display the firmware version
3.2
Non addressed transparent mode
This mode is entered then the address bits are all set to the off position and the modbus
disable bit is set to on. The meter type field is ignored.
In this mode the unit acts as a true RS232 to RS485 converter and all data on both ports
are forwarded to the other port. This mode is useful to daisy chain meters via RS485
when they are spaced further than the RS232 limit.
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3.3
Addressed transparent mode
This mode is entered then the address bits are set to a non zero address and the modbus
disable bit is set to on. The meter type field is ignored.
In this mode the unit acts as an addressable RS232 to RS485 converter. The unit uses a
frame based protocol in the form of:
<frame-delimiter><destination-addr><source-addr><payload><crc16><frame-delimiter>
This mode will allow non addressable devices/meters to be daisy chained onto a RS485
bus.
The protocol definition is available on request.
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Annexure A: Register Map
Instrumentation
Register Address
Description
Data type
100
Total Active Power
float32
102
Phase A Active Power
float32
104
Phase B Active Power
float32
106
Phase C Active Power
float32
108
Total Reactive Power
float32
110
Phase A Reactive Power
float32
112
Phase B Reactive Power
float32
114
Phase C Reactive Power
float32
116
Total Apparent Power
float32
118
Phase A Apparent Power
float32
120
Phase B Apparent Power
float32
122
Phase C Apparent Power
float32
124
Phase A Current Magnitude
float32
126
Phase B Current Magnitude
float32
128
Phase C Current Magnitude
float32
130
Frequency
float32
132
Phase A Voltage Magnitude
float32
134
Phase B Voltage Magnitude
float32
136
Phase C Voltage Magnitude
float32
138
System Power Factor
float32
140
Phase A Power Factor
float32
142
Phase B Power Factor
float32
144
Phase C Power Factor
float32
146
Phase A Current Angle
float32
148
Phase B Current Angle
float32
150
Phase C Current Angle
float32
152
Phase A Voltage Angle
float32
154
Phase B Voltage Angle
float32
156
Phase C Voltage Angle
float32
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Cumulatives
Register Address
Description
Data type
200
Import Wh
float64
204
Export Wh
float64
208
Q1 varh
float64
212
Q2 varh
float64
216
Q3 varh
float64
220
Q4 varh
float64
224
VAh
float64
228
Customer Defined 1
float64
232
Customer Defined 2
float64
236
Customer Defined 3
float64
240
Hist Import Wh
float64
244
Hist Export Wh
float64
248
Hist Q1 varh
float64
252
Hist Q2 varh
float64
256
Hist Q3 varh
float64
260
Hist Q4 varh
float64
264
Hist VAh
float64
268
Hist Customer Defined 1
float64
272
Hist Customer Defined 2
float64
276
Hist Customer Defined 3
float64
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Cumulatives (32bit Alternatives)
Register Address
Description
Data type
1200
Import Wh
float32
1202
Export Wh
float32
1204
Q1 varh
float32
1206
Q2 varh
float32
1208
Q3 varh
float32
1210
Q4 varh
float32
1212
VAh
float32
1214
Customer Defined 1
float32
1216
Customer Defined 2
float32
1218
Customer Defined 3
float32
1240
Hist Import Wh
float32
1242
Hist Export Wh
float32
1244
Hist Q1 varh
float32
1246
Hist Q2 varh
float32
1248
Hist Q3 varh
float32
1250
Hist Q4 varh
float32
1252
Hist VAh
float32
1254
Hist Customer Defined 1
float32
1256
Hist Customer Defined 2
float32
1258
Hist Customer Defined 3
float32
Time of use
Register Address
Description
Data type
300
TOU1
float64
304
TOU2
float64
308
TOU3
float64
312
TOU4
float64
316
HIST_TOU1
float64
320
HIST_TOU2
float64
324
HIST_TOU3
float64
328
HIST_TOU4
float64
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Time of use (32bit Alternatives)
Register Address
Description
Data type
1300
TOU1
float32
1302
TOU2
float32
1304
TOU3
float32
1306
TOU4
float32
1316
HIST_TOU1
float32
1318
HIST_TOU2
float32
1320
HIST_TOU3
float32
1322
HIST_TOU4
float32
Maximum Demand
Register Address
Description
Data type
500
MD1
float64
504
MD2
float64
508
MD3
float64
512
MD4
float64
516
MD1 date
int32
518
MD2 date
int32
520
MD3 date
int32
522
MD4 date
int32
524
HIST_MD1
float64
528
HIST_MD2
float64
532
HIST_MD3
float64
536
HIST_MD4
float64
540
HIST_MD1 date
int32
542
HIST_MD2 date
int32
544
HIST_MD3 date
int32
546
HIST_MD4 date
int32
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Maximum Demand (32bit Alternatives)
Register Address
Description
Data type
1500
MD1
float32
1502
MD2
float32
1504
MD3
float32
1506
MD4
float32
1524
HIST_MD1
float32
1526
HIST_MD2
float32
1528
HIST_MD3
float32
1530
HIST_MD4
float32
Multi Utility
Register Address
Description
Data type
600
MULTI_UTIL1
float64
604
MULTI_UTIL2
float64
608
MULTI_UTIL3
float64
612
MULTI_UTIL4
float64
616
HIST_MULTI_UTIL1
float64
620
HIST_MULTI_UTIL2
float64
624
HIST_MULTI_UTIL3
float64
628
HIST_MULTI_UTIL4
float64
Multi Utility (32bit Alternatives)
Register Address
Description
Data type
1600
MULTI_UTIL1
float32
1602
MULTI_UTIL2
float32
1604
MULTI_UTIL3
float32
1606
MULTI_UTIL4
float32
1616
HIST_MULTI_UTIL1
float32
1618
HIST_MULTI_UTIL2
float32
1620
HIST_MULTI_UTIL3
float32
1622
HIST_MULTI_UTIL4
float32
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General
Register Address
Description
Data type
400
Meter Date (seconds since 1 Jan 1970)
uint32
402
Uptime
uint32
404
Version
uint32
420
Meter Serial Number digit 1 and 2
uint16
421
Meter Serial Number digit 3 and 4
uint16
422
Meter Serial Number digit 5 and 6
uint16
423
Meter Serial Number digit 7 and 8
uint16
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Annexure B: Status indication
Status LED (A)
Modbus enabled (Address > 0), meter found:
80ms on/80ms 0ff/80ms on/3s off, repeat
Modbus enabled (Address > 0), meter not found:
500ms on/500ms 0ff, repeat
Modbus enabled (Address = 0), invalid setting:
All LEDS 100ms on/100ms 0ff, repeat
Modbus disabled (Address = 0), non addressed transparent mode:
100ms on/1000ms 0ff, repeat
Modbus disabled (Address > 0), addressed transparent mode:
100ms on/100ms 0ff/100ms on/1000ms off, repeat
RS232 Receive LED (B)
Indicates incoming data on the RS232 interface.
RS232 Transmit LED (C)
Indicates outgoing data on the RS232 interface.
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RS485 Receive LED (D)
Indicates incoming data on the RS485 interface.
RS485 Transmit LED (E)
Indicates outgoing data on the RS485 interface.
Program mode
LEDS will show a walking 'on' from left to right.
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Annexure C: Pinouts
RS232 – RJ12
Pin Number
Name
Direction
Description
1
Tx
Output
Transmit data output
2
Rx
Input
Receive data input
3
N/C
Not used 4
N/C
Not used
5
0V
Power supply common
6
V+
Power supply voltage (5..12VDC)
RS485 – RJ12
Pin Number
Name
Direction
Description
1 A
Bidir
Positive RS485 signal
2 B
Bidir
Negative RS485 signal
3
N/C
4
N/C
5
N/C
6
N/C
7
N/C
8
N/C
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Annexure D: USB Adapter
Configuration of the modem on a PC is done via a USB adapter that provides the
communications interface and PSU.
The FTDI controller chip is used in the adapter. The newest driver is available at
www.ftdichip.com
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Annexure E: Python Code Examples
readInstrumentation.py
import sys
import getopt
import struct
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
def getFloatBigEndian(client,unit, address):
regs = client.read_input_registers(address=address, count=2, unit=unit).registers
ii = regs[0] * 0x10000 + regs[1]
f = struct.unpack('f', struct.pack('I', ii))
return f[0]
def getFloatArray(client,unit,address,count):
values = []
startAddress = address
for i in xrange(0, count):
f = getFloatBigEndian(client=client,unit=unit, address=startAddress)
values.append(f)
startAddress = startAddress + 2;
return values
if name == ' main ':
labels = ['Ptot', 'Pa', 'Pb', 'Pc', 'Qtot', 'Qa', 'Qb', 'Qc', 'Stot', 'Sa', 'Sb', 'Sc', 'IaMag', 'IbMag', 'IcMag', 'Freq', 'Va', 'Vb', 'Vc', 'PFtot',
'PFa', 'PFb', 'PFc', 'IaAng', 'IbAng', 'IcAng', 'VaAng', 'VbAng', 'VcAng']
optlist, arglist = getopt.getopt(sys.argv[1:], 'p:a:')
serialPort = None
address = None
for option, value in optlist:
if option == '-p':
serialPort = str(value)
elif option == '-a':
address = int(value)
if serialPort is None or address is None:
print "Usage: python readInstrumentation.py -p <serial port> -a <modbus address>"
sys.exit()
client = ModbusClient(method='rtu', port=serialPort, parity='N', baudrate=9600, timeout=0.1)
values = getFloatArray(client=client,unit=address, address=100, count=29)
for ndx in range(len(values)):
print labels[ndx], '\t', values[ndx]
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readCumulatives.py
import sys
import getopt
import struct
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
def getFloatBigEndian(client,unit, address):
regs = client.read_input_registers(address=address, count=2, unit=unit).registers
ii = regs[0] * 0x10000 + regs[1]
f = struct.unpack('f', struct.pack('I', ii))
return f[0]
def getDoubleBigEndian(client, unit, address):
try:
tmpaddress = int(address)
tmpunit = int(unit)
except:
try:
return None
regs = client.read_input_registers(address=tmpaddress, count=4, unit=tmpunit).registers
p = struct.pack('!HHHH', regs[0], regs[1], regs[2], regs[3])
f = struct.unpack('!d', p)
return f[0]
except Exception, e:
print 'Modbus error reading '+str(address)+' from unit '+str(unit)+':', str(e)
return None
def getDoubleArray(client,unit,address,count):
values = []
startAddress = address
for i in xrange(0, count):
f = getDoubleBigEndian(client=client,unit=unit, address=startAddress)
values.append(f)
startAddress = startAddress + 4;
return values
if name == ' main ':
labels = ['ImportWh', 'ExportWh', 'Q1varh', 'Q2varh', 'Q3varh', 'Q4varh', 'VAh']
optlist, arglist = getopt.getopt(sys.argv[1:], 'p:a:')
serialPort = None
address = None
for option, value in optlist:
if option == '-p':
serialPort = str(value)
elif option == '-a':
address = int(value)
if serialPort is None or address is None:
print "Usage: python readCumulatives.py -p <serial port> -a <modbus address>"
sys.exit()
client = ModbusClient(method='rtu', port=serialPort, parity='N', baudrate=9600, timeout=0.1)
values = getDoubleArray(client=client,unit=address, address=200, count=7)
for ndx in range(len(values)):
print labels[ndx], '\t', values[ndx]
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readTOU.py
import sys
import getopt
import struct
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
def getFloatBigEndian(client,unit, address):
regs = client.read_input_registers(address=address, count=2, unit=unit).registers
ii = regs[0] * 0x10000 + regs[1]
f = struct.unpack('f', struct.pack('I', ii))
return f[0]
def getDoubleBigEndian(client, unit, address):
try:
tmpaddress = int(address)
tmpunit = int(unit)
except:
try:
return None
regs = client.read_input_registers(address=tmpaddress, count=4, unit=tmpunit).registers
p = struct.pack('!HHHH', regs[0], regs[1], regs[2], regs[3])
f = struct.unpack('!d', p)
return f[0]
except Exception, e:
print 'Modbus error reading '+str(address)+' from unit '+str(unit)+':', str(e)
return None
def getDoubleArray(client,unit,address,count):
values = []
startAddress = address
for i in xrange(0, count):
f = getDoubleBigEndian(client=client,unit=unit, address=startAddress)
values.append(f)
startAddress = startAddress + 4;
return values
if name == ' main ':
labels = ['TOU1', 'TOU2', 'TOU3', 'TOU4']
optlist, arglist = getopt.getopt(sys.argv[1:], 'p:a:')
serialPort = None
address = None
for option, value in optlist:
if option == '-p':
serialPort = str(value)
elif option == '-a':
address = int(value)
if serialPort is None or address is None:
print "Usage: python readTOU.py -p <serial port> -a <modbus address>"
sys.exit()
client = ModbusClient(method='rtu', port=serialPort, parity='N', baudrate=9600, timeout=0.1)
values = getDoubleArray(client=client,unit=address, address=300, count=4)
for ndx in range(len(values)):
print labels[ndx], '\t', values[ndx]
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readMD.py
import sys
import getopt
import struct
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
def getIntBigEndian(client,unit, address):
regs = client.read_input_registers(address=address, count=2, unit=unit).registers
i = regs[0] * 0x10000 + regs[1]
return i
def getDoubleBigEndian(client, unit, address):
try:
tmpaddress = int(address)
tmpunit = int(unit)
except:
try:
return None
regs = client.read_input_registers(address=tmpaddress, count=4, unit=tmpunit).registers
p = struct.pack('!HHHH', regs[0], regs[1], regs[2], regs[3])
f = struct.unpack('!d', p)
return f[0]
except Exception, e:
print 'Modbus error reading '+str(address)+' from unit '+str(unit)+':', str(e)
return None
def getIntArray(client,unit,address,count):
values = []
startAddress = address
for i in xrange(0, count):
f = getIntBigEndian(client=client,unit=unit, address=startAddress)
values.append(f)
startAddress = startAddress + 2;
return values
def getDoubleArray(client,unit,address,count):
values = []
startAddress = address
for i in xrange(0, count):
f = getDoubleBigEndian(client=client,unit=unit, address=startAddress)
values.append(f)
startAddress = startAddress + 4;
return values
if name == ' main ':
labels = ['MD1', 'MD2', 'MD3', 'MD4']
optlist, arglist = getopt.getopt(sys.argv[1:], 'p:a:')
serialPort = None
address = None
for option, value in optlist:
if option == '-p':
serialPort = str(value)
elif option == '-a':
address = int(value)
if serialPort is None or address is None:
print "Usage: python readMD.py -p <serial port> -a <modbus address>"
sys.exit()
client = ModbusClient(method='rtu', port=serialPort, parity='N', baudrate=9600, timeout=0.1)
values = getDoubleArray(client=client,unit=address, address=500, count=4)
ts = getIntArray(client=client,unit=address, address=516, count=4)
for ndx in range(len(values)):
print labels[ndx], '\t', values[ndx], ts[ndx]
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readMeterSerial.py
import sys
import getopt
import struct
from pymodbus.client.sync import ModbusSerialClient as ModbusClient
def regArrayToString(regs):
s = ''
for reg in regs:
s += chr((reg >> 8) & 0x00FF)
s += chr(reg & 0x00FF)
s = s.strip('\x00')
return s
if name == ' main ':
optlist, arglist = getopt.getopt(sys.argv[1:], 'p:a:')
serialPort = None
address = None
for option, value in optlist:
if option == '-p':
serialPort = str(value)
elif option == '-a':
address = int(value)
if serialPort is None or address is None:
print "Usage: python readMeterSerial.py -p <serial port> -a <modbus address>"
sys.exit()
client = ModbusClient(method='rtu', port=serialPort, parity='N', baudrate=9600, timeout=0.1)
regs = client.read_input_registers(address=420, count=4, unit=address).registers
print "Serial Number\t", regArrayToString(regs)
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