CET PMC-D721MD User manual

PMC-D721MD
Digital Multifunction Meter
User Manual
Version: V1.0
June 25, 2018

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This manual may not be reproduced in whole or in part by any means without the express
written permission from CET.
The information contained in this manual is believed to be accurate at the time of publication;
however, CET assumes no responsibility for any errors which may appear here and reserves
the right to make changes without notice. Please consult CET or your local representative
for the latest product specifications.
DANGER
This symbol indicates the presence of danger that may result in severe injury or death and
permanent equipment damage if proper precautions are not taken during the installation,
operation or maintenance of the device.
CAUTION
This symbol indicates the potential of personal injury or equipment damage if proper
precautions are not taken during the installation, operation or maintenance of the device.

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DANGER
Failure to observe the following instructions may result in severe injury or
death and/or equipment damage.

Installation, operation and maintenance of the meter should only be
performed by qualified, competent personnel that have the appropriate
training and experience with high voltage and current devices. The meter
must be installed in accordance with all local and national electrical codes.

Ensure that all incoming AC power and other power sources are turned OFF
before performing any work on the meter.

Before connecting the meter to the power source, check the label on top of
the meter to ensure that it is equipped with the appropriate power supply, and
the correct voltage and current input specifications for your application.

During normal operation of the meter, hazardous voltages are present on its
terminal strips and throughout the connected potential transformers (PT) and
current transformers (CT). PT and CT secondary circuits are capable of
generating lethal voltages and currents with their primary circuits energized.
Follow standard safety precautions while performing any installation or service
work (i.e. removing PT fuses, shorting CT secondaries…etc).

Do not use the meter for primary protection functions where failure of the
device can cause fire, injury or death. The meter should only be used for
shadow protection if needed.

Under no circumstances should the meter be connected to a power source if
it is damaged.

To prevent potential fire or shock hazard, do not expose the meter to rain or
moisture.

Setup procedures must be performed only by qualified personnel familiar with
the instrument and its associated electrical equipment.
DO NOT open the instrument under any circumstances.

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Limited warranty

CET offers the customer a minimum of 12-month functional warranty on the meter
for faulty parts or workmanship from the date of dispatch from the distributor.
This warranty is on a return to factory for repair basis.

CET does not accept liability for any damage caused by meter malfunctions. CET
accepts no responsibility for the suitability of the meter to the application for
which it was purchased.

Failure to install, set up or operate the meter according to the instructions herein
will void the warranty.

Only CET’s duly authorized representative may open your meter. The unit should
only be opened in a fully anti-static environment. Failure to do so may damage
the electronic components and will void the warranty.

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Table of Contents
Chapter 1 Introduction ............................................................................................................................. 7
1.1 Overview ....................................................................................................................................7
1.2 Features......................................................................................................................................7
1.3 Getting more information ..........................................................................................................8
Chapter 2 Installation ............................................................................................................................... 9
2.1 Appearance ................................................................................................................................9
2.2 Unit Dimensions .......................................................................................................................10
2.3 Mounting..................................................................................................................................10
2.4 Input Wiring .............................................................................................................................11
2.5 Communications Wiring ...........................................................................................................11
2.6 Digital Input Wiring ..................................................................................................................11
2.7 Pulse Output Wiring .................................................................................................................12
2.8 Power Supply Wiring ................................................................................................................12
Chapter 3 Front Panel............................................................................................................................. 13
3.1 Display ......................................................................................................................................13
3.1.1 LCD Testing....................................................................................................................13
3.1.2 LCD Display Areas..........................................................................................................13
3.2 Using the Front Panel Buttons..................................................................................................15
3.3 LED Pulse Outputs ....................................................................................................................15
3.4 Display Screen Types ................................................................................................................15
3.5 Setup Configuration via the Front Panel ..................................................................................15
3.5.1 Making Setup Changes..................................................................................................16
3.5.2 Setup Menu ..................................................................................................................16
3.5.3 Configuration ................................................................................................................17
Chapter 4 Applications ........................................................................................................................... 18
4.1 Digital Inputs ............................................................................................................................18
4.2 Pulse Outputs ...........................................................................................................................18
4.3 Basic Measurement..................................................................................................................18
4.4 SOE ...........................................................................................................................................18
Chapter 5 Modbus Register Map............................................................................................................ 19
5.1 Basic Measurements ................................................................................................................19
5.2 SOE Log.....................................................................................................................................19
5.3 Device Setup.............................................................................................................................21
5.3.1 Basic Setup Parameters.................................................................................................21
5.3.2 I/O Setup Parameters....................................................................................................21
5.3.3 Energy Pulse Setup Parameter......................................................................................21
5.3.4 Communication Setup Parameters ...............................................................................21
5.4 Time..........................................................................................................................................21
5.5 Clear Control ............................................................................................................................22
5.6 Meter Information....................................................................................................................22
Appendix A Technical Specifications....................................................................................................... 24

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Appendix B Standards Compliance......................................................................................................... 25
Appendix C Ordering Guide ....................................................................................................................26
Contact us............................................................................................................................................... 27

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Chapter 1 Introduction
This manual explains how to use the PMC-D721MD DC Multifunction Meter. Throughout the manual
the term “meter” generally refers to all models. Differences between the models are indicated with
the appropriate model number.
This chapter provides an overview of the PMC-D721MD meter and summarizes many of its key
features.
1.1 Overview
The PMC-D721MD DC Multifunction Meter is CET’s latest offer for the low-cost DC metering market.
Housed in an industry standard DIN form factor measuring 72mmx72mmx71.8mm, it is perfectly suited
for industrial, commercial and utility DC metering applications. The PMC-D721MD complies with Class
0.5S kWh Accuracy Standard and features quality construction, multifunction measurements and a
bright, easy to read LCD display. The PMC-D721MD comes standard with two front panel LED
indicators for Energy Pulsing and Communication. It optionally provides two Digital Inputs for Status
Monitoring and two Solid State Pulse Outputs for kWh Energy Pulsing applications. The standard SOE
Log records meter events such as power-off, setup changes and DI operations in 1ms resolution. With
the standard RS485 port and Modbus protocol support, the PMC-D721MD becomes a vital component
of an intelligent, multifunction monitoring solution for any DC Power and Energy Management systems.
You can setup the meter through its front panel or via our free PMC Setup software. The meter is also
supported by our PecStar® iEMS Integrated Energy Management System.
Following is a list of typical applications for the PMC- D721MD:
DC Inverter, DC Panel Metering and DC Charging Station
Industrial and commercial DC metering
DC Distribution Monitoring
Contact CET Technical Support should you require further assistance with your application.
1.2 Features
Ease of use
Large, backlit LCD display with wide viewing angle
Intuitive user interface
LED indicators for Energy Pulsing and Communication activities
Password-protected setup via front panel or free PMC Setup software
Easy installation with mounting clips, no tools required
Measurements
Voltage, Current and kW
Bi-directional kWh measurements
SOE Log
32 events time-stamped to ±1ms resolution
Record all setup and Digital Input status changes

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Inputs and Outputs
2xFront Panel LED indicators for Energy Pulsing and Communication
Optional 2xDigital Inputs for Status Monitoring
Optional 2xSolid State Relay for kWh Imp and kWh Exp Pulse Output.
Communications
Standard RS-485 port with Modbus RTU support at 1200 to 19,200 bps equipped
System Integration
Supported by CET’s PecStar® iEMS and PMC Setup
Easy integration into other Automation, SCADA or BMS systems via Modbus RTU
1.3 Getting more information
Additional information is available from CET via the following sources:
Visit www.cet-global.com
Contact your local representative
Contact CET directly via email or telephone

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Chapter 2 Installation
2.1 Appearance
Figure 2-1 Appearance
Figure 2-2 Rear Panel (2DIs + 2DOs)
Caution
Installation of the PMC-D721MD should only be performed by qualified, competent
personnel that have the appropriate training and experience with high voltage and current
devices. The meter must be installed in accordance with all local and national electrical
codes.
During the operation of the meter, hazardous voltages are present at the input terminals.
Failure to observe precautions can result in serious or even fatal injury and equipment
damage.

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2.2 Unit Dimensions
Figure 2-3 Dimension
2.3 Mounting
The PMC-D721MD meter should be installed in a dry environment with no dust and kept away from
heat, radiation and electrical noise source.
Installation steps:
Remove the installation clips from the meter
Fit the meter through a 68mmx68mm cutout as shown in Figure 2-4
Re-install the installation clips and push the clips tightly against the panel to secure the meter
Figure 2-4 Panel Cutout

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2.4 Input Wiring
Please consult the serial number label to ensure that the voltage and current input is less than or equal
to the meter’s input specification.
Figure 2-5 Input Connections
2.5 Communications Wiring
The following figure illustrates the RS485 communications connections on the PMC-D721MD:
Figure 2-6 Communications Connections
The PMC-D721MD provides one RS485 port and supports the Modbus RTU protocol. Up to 32 devices
can be connected on a RS485 bus. The overall length of the RS485 cable connecting all devices should
not exceed 1200m.
If the master station does not have a RS485 communications port, a RS232/RS485 or USB/RS485
converter with optically isolated output and surge protection should be used.
2.6 Digital Input Wiring
The following figure illustrates the Digital Input connections on the PMC-D721MD:
Figure 2-7 DI Connections

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2.7 Pulse Output Wiring
The following figure illustrates the Pulse Output connections on the PMC-D721MD:
Figure 2-8 Pulse Output Connections
2.8 Power Supply Wiring
For AC supply, connect the live wire to the L/+ terminal and the neutral wire to the N/- terminal.
For DC supply, connect the positive wire to the L/+ terminal and the negative wire to the N/- terminal.
Figure 2-9 Power Supply Connections

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Chapter 3 Front Panel
The PMC-D721MD meter has a large, bright, backlit LCD display and four buttons for data display and
meter configuration. This chapter introduces the front panel operations.
Figure 3-1 Front Panel
3.1 Display
3.1.1 LCD Testing
Pressing both the <Phase> and the <Energy> buttons simultaneously for 2 seconds enters the LCD
Testing mode. All LCD segments are illuminated during testing. The LCD will return to its normal
display mode when any button is pressed.
Figure 3-2 Full LED/LCD Display
3.1.2 LCD Display Areas
This section provides a description of the LCD display areas. The PMC-D721MD with LCD display can
generally be divided into 4 areas:
A: Measurement symbols for Voltage and Current. Other symbols such as THD, Unbalance, PF,
Voltage Phase Angle, Current Phase Angle and Demand are reserved.
B: Measurement values
C: Measurement Units of kW and kWh. Other symbols such as Comm. Indicator, Hz, kvar/kvarh,
kVA/kVAh, PF Quadrant status symbols, mA and °C are reserved.

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D: DI Status and kWh Imp/Exp indicators. DO Status and kWh Net/Total indicators are reserved.
Figure 3-3 LCD Display
The following table shows the special LCD display symbols:
NO.
Label
Description
A
Voltage
Current
Reserved
C
Measurement Units of Power (kW) and Energy (kWh).
Reserved
D
DI Open
DI Close
Import
Export
Reserved
Table 3-1 LCD Display Symbols

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3.2 Using the Front Panel Buttons
The button definitions under Data Display Mode and Setup Configuration Mode are explained in the
following table. The default password is 0.
Buttons
Data Display Mode
Setup Configuration Mode
<U/I>
Pressing <U/I> views the Voltage
and Current measurements.
Once a parameter is selected, pressing this
button moves the cursor to the left by one
position if the parameter being changed is a
numeric value.
<Power>
Pressing <Power> views the kW
measurements.
Before a parameter is selected for modification,
pressing this button advances to the next
parameter in the menu.
If a parameter is already selected, pressing this
button increments a numeric value or advances
to the next value in the selection list.
<Energy>
Pressing <Energy> views kWh
Import and kWh Export
parameters.
Before a parameter is selected for modification,
pressing this button goes back to the last
parameter in the menu.
If a parameter is already selected, pressing this
button decrements a numeric value or goes back
to the last value in the selection list.
<Setup>
This button is ignored.
Pressing this button for more than two seconds
toggles between Data Display mode and Setup
Configuration mode.
Once inside the Setup Configuration mode and at
the main menu, pressing this button selects a
sub-menu or a parameter for modification.
After changing the parameter, pressing this
button again saves the new setting into memory.
Table 3-2 Buttons Description
3.3 LED Pulse Outputs
The PMC-D721MD comes standard with one LED indicator for Energy Pulse Output which can be used
for kWh energy pulsing if the EN PULSE is enabled (see Section 4.2 LED Pulse Outputs for more
information) and a second LED indicator for Communication Status.
3.4 Display Screen Types
The front panel provides two display modes: Data Display and Setup Configuration. There are four
buttons on the front panel: <U/I>, <Power>, <Energy> and <Setup>. The <Setup> button is only used
when configuring the meter.
The following table illustrates the display screens for the PMC-D721MD model.
Press button
Display screens
First row
Second row
Third row
<U/I>
Display 1 (default)
-
Voltage
Current
<Power>
Display 1
-
Power
-
<Energy>
Display 1
kWh Import
Display 2
kWh Export
Table 3-3 PMC-D721MD Data Display Screens
3.5 Setup Configuration via the Front Panel
Pressing the <Setup> button for more than 2 seconds enters the Setup Configuration mode where the
setup parameters can be changed. Upon completion, pressing the <Setup> button for more than 2
seconds returns to the Data Display mode.

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3.5.1 Making Setup Changes
1) Entering the Password:
Press the <Setup> button for more than 2 seconds to access Setup Configuration mode.
Press the <Energy> button to advance to the Password page.
A correct password must be entered before changes are allowed. The factory default password
is zero. Press the <Setup> button to select the parameter for modification. Use the <U/I>,
<Power> and <Energy> buttons to enter the correct password.
2) Selecting a parameter to change:
Use the < Power > and <Energy> button to scroll to the desired parameter.
Press the <Setup> button to select the parameter. Once selected, the parameter value will blink.
3) Changing and saving a parameter:
Use the <U/I>, <Power> and <Energy> buttons to make modification to the selected parameter.
After modification, press the <Setup> button to save the new value into memory.
If necessary, pressing the <U/I> button from inside a sub-menu to return to the main menu.
4) Returning to Data Display mode:
Pressing the <Setup> button for more than 2 seconds to return to the default display screen.
3.5.2 Setup Menu
Figure 3-3 Setup Menu

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3.5.3 Configuration
The Setup Configuration mode provides access to the following setup parameters:
Label
Parameters
Description
Range
Default
Menu
Main Sub
PROG
Programming
Setup Configuration
Mode
/
/
PASS
Password
Enter Password
0 to 9999
“0”
PASS SET
Change Password
NEW PASS
New Password
Change Password
0000 to 9999
“0”
SYS SET
Setup System Parameters
Un
Unominal
Set nominal Voltage
1 to 1000V
750
I E
Inominal
Set nominal Current
1 to 10000A
100
SH
Shunt Output
Set Shunt Nom. Output
1 to 100mV
75
BLTO
Backlight Time-
Out
Set Backlight Time-out
0 to 60 mins
3
COM SET
Setup Comm. Parameters
ID
Meter Address
Set Modbus Unit ID
1-247
100
BAUD
Baud rate
Set Data rate in bits per
second
1200/2400/4800/
9600/19200bps
9600
CFG
Data Format
Set Comm. Port
Configuration
8N2/8O1/8E1/8N1/
8O2/ 8E2
8E1
ENGY SET
Setup Energy Outputs Parameters and Preset kWh Import/Export.
ENGY PULS
Energy Pulsing
Enable Energy Pulsing
YES/NO
YES
ENGY CNST
Pulse Constant
Pulse Constant
25/100/400/1000/
3200 imp/kWh
100
kWh Import
kWh Import
Preset kWh Import
0 to 99,999,999.9
0
kWh Export
kWh Export
Preset kWh Export
0 to 99,999,999.9
0
IO SET1
Specifies the minimum duration the DI must remain in the Active or Inactive
state before a state change is considered to be valid.
DI1
DI1 Debounce
DI1 Debounce
1 to 9999ms
20
DI2
DI2 Debounce
DI2 Debounce
1 to 9999ms
20
CLR
ENEY
Clear Energy
Clear Energy Registers
YES/NO
NO
SOE CLR
Clear SOE
Clear SOE Log
YES/NO
NO
ALL CLR
Clear All Records
Clear Energy Registers
and SOE Log
YES/NO
NO
TM SET
Setup Date and Clock
DATE
Date
Enter the Current Date
YYYY-MM-DD
/
CLK
Clock
Enter the Current Time
HH:MM:SS
/
INFO
Check meter information
FW
Firmware
Version
Firmware Version
e.g. 1.00.00 means
V1.00.00
/
PROT VER
Protocol Version
Protocol Version
e.g. 1.0 means V1.0
/
UPDT
Update Date
Firmware Update Date
e.g. 20130603
/
Table 3-4 Setup Parameters
Notes:
1) The I/O setup parameters are only displayed when the PMC-D721MD is equipped with this option.

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Chapter 4 Applications
4.1 Digital Inputs
The PMC-D721MD comes optionally with two self-excited Digital Inputs that are internally wetted at 24
VDC. Digital Inputs are typically used for monitoring external status which can help prevent equipment
damage, improve maintenance and track security breaches. The real-time statuses of the Digital
Inputs are available on the front panel LCD Display as well as through communications. Changes in
Digital Input status are stored as events in the SOE Log in 1 ms resolution.
4.2 Pulse Outputs
The PMC-D721MD comes standard with one front panel LED Pulse Output for Energy Pulsing and can
be equipped with two optional Solid Relay Output for kWh Imp and kWh Exp energy pulsing where DO
Energy Pulse Outputs are typically used for accuracy testing. Energy pulsing can be enabled from the
front panel through the ENGY PULS setup parameter. The pulse constant can be configured as
25/100/400/1000/3200 imp/kWh through the ENGY CNST setup parameter.
4.3 Basic Measurement
The PMC-D721MD provides following basic measurements which are available through the LCD display
or communication:
Voltage, Current and kW
kWh Import and kWh Export
4.4 SOE
The PMC-D721MD can store up to 32 events such as Power-On, Power-Off, Digital Input status changes
and setup changes in its non-volatile memory. Each event record includes the event classification, its
relevant parameter values and a timestamp in 1ms resolution.
All event records can be retrieved via communications. If there are more than 32 events, the newest
event will replace the oldest event on a First-In-First-Out basis. The SOE Log can be reset from the
front panel or via communications.

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Chapter 5 Modbus Register Map
This chapter provides a complete description of the Modbus register map (Protocol Versions 1.0 and
above) for the PMC-D721MD Digital Multifunction Meter to facilitate the development of 3rd party
communications driver for accessing information on the PMC-D721MD.
The PMC-D721MD supports the following Modbus functions:
1) Read Holding Registers (Function Code 0x03)
2) Force Single Coil (Function Code 0x05)
3) Preset Multiple Registers (Function Code 0x10)
The following table provides a description of the different data formats used for the Modbus registers.
The PMC-D721MD uses the Big Endian byte ordering system.
Format
Description
UINT16/INT16
Unsigned/Signed 16-bit Integer
UINT32/INT32
Unsigned/Signed 32-bit Integer
Float
IEEE 754 32-bit
Single Precision Floating Point Number
For a complete Modbus Protocol Specification, please visit www.modbus.org.
5.1 Basic Measurements
Register
Property
Description
Format
Scale
Unit
0000
RO
U
Float
x1
V
0002
RO
I
Float
x1
A
0004
RO
kW
Float
x1
W
0006-0029
RO
Reserved
0030
RO
DI Status
UINT16
0031
RO
Reserved
0032
RO
SOE Pointer
UINT32
0034-0039
RO
Reserved
0040
RO
kWh Import
INT32
x0.01
kWh
0042
RO
kWh Export
INT32
x0.01
kWh
Table 5-1 Basic Measurements
Notes:
1) For the DI Status register, the bit values of B0 and B1 represent the states of DI1 and DI2,
respectively, with “1” meaning active (closed) and “0” meaning inactive (open).
2) The range of the SOE Pointer is between 0 and 0xFFFFFFFF and it is incremented by one for every
new log generated and will roll over to 0 if its current value is 0xFFFFFFFF. A value of zero
indicates that the SOE does not contain any Log. If a SOE CLR is performed from the front panel
or via communications, the SOE Pointer will be reset to zero and then immediately incremented
by one with a new ”Setup Changes via Front Panel” or “Setup Changes via Communications” event.
Therefore, any 3rd party software should assume that a SOE CLR E action has been performed if it
sees the SOE Pointer rolling over to one or to a value that is smaller than its own pointer. In this
case, the new SOE Pointer also indicates the number of events in the SOE Log if it is less than 32.
Otherwise, there will always be 32 events in the SOE Log.
5.2 SOE Log
The SOE Log Pointer points to the register address within the SOE Log where the next event will be
stored. The following formula is used to determine the register address of the most recent SOE event
referenced by the SOE Log Pointer value:
Register Address = 10000 + Modulo(SOE Log Pointer-1/32)*8
Register
Property
Description
Format
10000~10007
RO
Event 1
See
Table 5-3 SOE Log
10008~10015
RO
Event 2

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10016~10023
RO
Event 3
Data Structure
10024~10031
RO
Event 4
10032~10039
RO
Event 5
10040~10047
RO
Event 6
10048~10055
RO
Event 7
10056~10063
RO
Event 8
10064~10071
RO
Event 9
10072~10079
RO
Event 10
10080~10087
RO
Event 11
10088~10095
RO
Event 12
…
…
10248~10255
RO
Event 32
Table 5-2 SOE Log
Notes:
1) SOE LOG Data Structure
Offset
Property
Description
Unit
+0
RO
High-order Byte: Event Classification2
-
RO
Low-order Byte: Sub-Classification2
-
+1
RO
Record Time: Year
0-99 (Year-2000)
RO
Record Time: Month
1 to 12
+2
RO
Record Time: Day
1 to 31
RO
Record Time: Hour
0 to 23
+3
RO
Record Time: Minute
0 to 59
RO
Record Time: Second
0 to 59
+4
RO
Record Time: Millisecond
0 to 999
+5
RO
High-order Byte: Reserved
-
RO
Low-order Byte: Status2
-
+6 to +7
RO
Event Value2
-
Table 5-3 SOE LOG Data Structure
2) SOE Event Classification
Table 5-4 SOE Event Classification
Event
Classification
Sub-
Classification
Status
Event
Value
Description
1= DI Change
1
1 / 0
1/0
DI1 Inactive / DI1 Active
2
1 / 0
1/0
DI2 Inactive / DI2 Active
4 = Self-
diagnosis
1
None
None
System Parameter Fault
2
Interval Parameter Fault
5=Operations
1
None
None
Reserved
2
Power Off
3
Set Clock via Front Panel
4
System Parameter Changes via Front Panel
5
Internal Parameter Changes via Front Panel
6
Comm. Parameter Changes via Front panel
7
Preset kWh via Front Panel
8
Clear SOE via Front Panel
9
Clear Energy Registers via Front Panel
10
Clear All Records (SOE Log and Energy
Registers) via Front Panel
11
System Parameters Changes via
Communications
12
Internal Parameter Changes via
Communications
13
Comm. Parameter Changes via
Communications
14
Preset kWh via Communications
15
Clear SOE via Communications
16
Clear Energy Registers via Communications
17
Clear All Records (SOE Log and Energy
Registers) via Communications