Maxim Integrated 71M6533-DB User Manual
71M6533-DB Demo Board
USER’S MANUAL
Page: 1 of 75 ` REV 3
71M6533
3-Phase Energy Meter IC
DEMO BOARD 71M6533-DB
USER’S MANUAL
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent
licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integr ated Products, Inc. 160 Rio R obles, San Jose, CA 95134 USA 1-408-601-1000
2012 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Page: 2 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
Table of Contents
1 GETTING STARTED................................................................................................................................................ 7
1.1 General .................................................................................................................................................................... 7
1.2 Safety and ESD Notes ............................................................................................................................................ 7
1.3 Demo Kit Contents ................................................................................................................................................. 7
1.4 Demo Board Versions ............................................................................................................................................ 7
1.5 Compatibility ........................................................................................................................................................... 8
1.6 Suggested Equipment not Included ..................................................................................................................... 8
1.7 Demo Board Test Setup ......................................................................................................................................... 8
1.7.1 Setup with USB-to-Serial Adapter ..................................................................................................................... 9
1.7.2 Power Supply Setup ........................................................................................................................................ 10
1.7.3 Checking Operation......................................................................................................................................... 10
1.7.4 Serial Connection Setup .................................................................................................................................. 11
1.8 Using the Demo Board ......................................................................................................................................... 13
1.8.1 Serial Command Language ............................................................................................................................. 13
1.8.2 Using the Demo Board for Energy Measurements .......................................................................................... 21
1.8.3 Adjusting the Kh Factor for the Demo Board ................................................................................................... 21
1.8.4 Adjusting the Demo Boards to Different Current Transformers ....................................................................... 21
1.8.5 Adjusting the Demo Boards to Different Voltage Dividers ................................................................ ............... 22
1.9 Calibration Parameters ........................................................................................................................................ 23
1.9.1 General Calibration Procedure ................................................................ ........................................................ 23
1.9.2 Calibration Macro File ..................................................................................................................................... 24
1.9.3 Updating the Demo Code (hex file) ................................................................................................................. 24
1.9.4 Updating Calibration Data in Flash or EEPROM ............................................................................................. 24
1.9.5 Automatic Gains Calibration ............................................................................................................................ 25
1.9.6 Loading the Code for the 6533 into the Demo Board ...................................................................................... 25
1.9.7 The Programming Interface of the 71M6533 ................................................................................................... 27
1.10 Demo Code ........................................................................................................................................................ 27
1.10.1 Demo Code Description ............................................................................................................................... 27
1.10.2 Important Demo Code MPU Parameters ..................................................................................................... 27
1.10.3 Useful CLI Commands Involving the MPU and CE ...................................................................................... 33
2 APPLICATION INFORMATION ............................................................................................................................. 35
2.1 Calibration Theory ................................................................................................................................................ 35
2.1.1 Calibration with Three Measurements ............................................................................................................. 35
2.1.2 Calibration with Five Measurements ............................................................................................................... 37
2.2 Calibration Procedures ........................................................................................................................................ 38
2.2.1 Calibration Procedure with Three Measurements ........................................................................................... 39
2.2.2 Calibration Procedure with Five Measurements ................................ .............................................................. 40
2.2.3 Calibration Procedure for Rogowski Coil Sensors ........................................................................................... 40
2.2.4 Calibration Spreadsheets ................................................................................................................................ 41
2.2.5 Compensating for Non-Linearities ................................................................................................................... 45
2.3 Power Saving Measures ...................................................................................................................................... 46
2.4 Schematic Information ......................................................................................................................................... 46
2.4.1 Components for the V1 Pin ............................................................................................................................. 46
2.4.2 Reset Circuit .................................................................................................................................................... 46
2.4.3 Oscillator ......................................................................................................................................................... 47
2.4.4 EEPROM ......................................................................................................................................................... 47
2.4.5 LCD ................................................................................................................................................................. 48
2.4.6 Optical Interface .............................................................................................................................................. 48
2.4.7 Ferrites ............................................................................................................................................................ 49
Page: 3 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
2.5 Testing the Demo Board ...................................................................................................................................... 49
2.5.1 Functional Meter Test ...................................................................................................................................... 49
2.5.2 EEPROM ......................................................................................................................................................... 51
2.5.3 RTC ................................................................................................................................................................. 51
2.5.4 Hardware Watchdog Timer ............................................................................................................................. 52
2.5.5 LCD ................................................................................................................................................................. 52
2.6 Application Notes ................................................................................................................................................. 53
3 HARDWARE DESCRIPTION ................................................................................................................................. 55
3.1 71M6533 Board Description: Jumpers, Switches and Test Points .................................................................. 55
3.2 Board Hardware Specifications .......................................................................................................................... 58
4 APPENDIX ............................................................................................................................................................. 59
4.1 71M6533-DB Demo Board Electrical Schematic ................................................................................................ 60
4.2 71M6533-DB Demo Board Bill of Material .......................................................................................................... 63
4.3 71M6533-DB Demo Board PCB Layout............................................................................................................... 64
4.4 71M6533 Pin-Out Information .............................................................................................................................. 70
5 REVISION HISTORY ............................................................................................................................................. 75
List of Figures
Figure 1-1: Block Diagram for the 71M6533-DB Demo Board with Debug Board ............................................................... 9
Figure 1-2: DB6534T14A3 Demo Board with USB-to-Serial Adapter................................................................................ 10
Figure 1-3: Hyperterminal Sample Window with Disconnect Button (Arrow) ..................................................................... 12
Figure 1-4: Port Speed and Handshake Setup (left) and Port Bit setup (right) .................................................................. 12
Figure 1-5: Command Line Help Display .......................................................................................................................... 13
Figure 1-6: Typical Calibration Macro File ......................................................................................................................... 24
Figure 1-7: Emulator Window Showing Reset and Erase Buttons (see Arrows) ............................................................... 26
Figure 1-8: Emulator Window Showing Erased Flash Memory and File Load Menu......................................................... 26
Figure 2-1: Watt Meter with Gain and Phase Errors. ......................................................................................................... 35
Figure 2-2: Phase Angle Definitions .................................................................................................................................. 39
Figure 2-3: Calibration Spreadsheet for Three Measurements ......................................................................................... 42
Figure 2-4: Calibration Spreadsheet for Five Measurements ............................................................................................ 43
Figure 2-5: Calibration Spreadsheet for Rogowski coil ..................................................................................................... 44
Figure 2-6: Non-Linearity Caused by Quantification Noise ............................................................................................... 45
Figure 2-7: Voltage Divider for V1 ..................................................................................................................................... 46
Figure 2-8: External Components for RESETZ ................................................................................................................. 47
Figure 2-9: Oscillator Circuit .............................................................................................................................................. 47
Figure 2-10: EEPROM Circuit ........................................................................................................................................... 48
Figure 2-11: LCD Connections .......................................................................................................................................... 48
Figure 2-12: Optical Interface Block Diagram ................................................................................................................... 49
Figure 2-13: Meter with Calibration System ...................................................................................................................... 50
Figure 2-14: Calibration System Screen ........................................................................................................................... 50
Figure 2-15: Wh Load Line in Differential Mode at Room Temperature ............................................................................ 51
Figure 3-1: 71M6533-DB Demo Board - Board Description .............................................................................................. 57
Figure 4-1: 71M6533-DB Demo Board: Electrical Schematic 1/3...................................................................................... 60
Figure 4-2: 71M6533-DB Demo Board: Electrical Schematic 2/3...................................................................................... 61
Figure 4-3: 71M6533-DB Demo Board: Electrical Schematic 3/3...................................................................................... 62
Figure 4-4: 71M6533-DB Demo Board: Top View ............................................................................................................. 64
Figure 4-5: 71M6533-DB Demo Board: Top Copper ......................................................................................................... 65
Figure 4-6: 71M6533-DB Demo Board: Middle Layer 1 (Ground Plane) ........................................................................... 66
Figure 4-7: 71M6533-DB Demo Board: Middle Layer 2 (Supply Plane) ............................................................................ 67
Figure 4-8: 71M6533-DB Demo Board: Bottom Copper .................................................................................................... 68
Figure 4-9: 71M6533-DB Demo Board: Bottom View ........................................................................................................ 69
Figure 4-10: 71M6533/71M6533H epLQFP100: Pin Out (top view) .................................................................................. 73
Page: 4 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
List of Tables
Table 1-1: Selectable Display Options .............................................................................................................................. 11
Table 1-2: CE RAM Locations for Calibration Constants .................................................................................................. 23
Table 1-3: Flash Programming Interface Signals .............................................................................................................. 27
Table 1-4: MPU Input Parameters for Metering................................................................................................................. 29
Table 1-5: Selectable Pulse Sources ................................................................ ................................................................ 30
Table 1-6: MPU Instantaneous Output Variables .............................................................................................................. 30
Table 1-7: MPU Status Word Bit Assignment ................................................................................................................... 32
Table 1-8: MPU Accumulation Output Variables ............................................................................................................... 33
Table 1-9: CLI Commands for Data Memory .................................................................................................................... 33
Table 2-1: Power Saving Measures ................................................................................................................................ .. 46
Table 3-1: 71M6533-DB Demo Board Description ............................................................................................................ 55
Table 3-2: 71M6533-DB Demo Board Description ............................................................................................................ 56
Table 3-3: 71M6533-DB Demo Board Description ............................................................................................................ 57
Table 4-1: 71M6533-DB Demo Board: Bill of Material ...................................................................................................... 63
Table 4-2: 71M6533/71M6533H Pin Description Table 1/3 ............................................................................................... 70
Table 4-3: 71M6533/71M6533H Pin Description Table 2/3 ............................................................................................... 70
Table 4-4: 71M6533/71M6533H Pin Description Table 3/3 ............................................................................................... 72
Page: 5 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
Page: 6 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
1
Teridian is a trademark of Maxim Integrated Products, Inc.
1 GETTING STARTED
1.1 GENERAL
The Teridian™ 71M6533-DB Demo Board is a demonstration board for evaluating the 71M6533 device for 3phase electronic power metering applications. It incorporates a 71M6533 integrated circuit, peripheral circuitry
such as a serial EEPROM, emulator port, and on-board power supply as well as a USB-to-serial adapter that
allows a connection to a PC through the USB port. The demo board allows the evaluation of the 71M6533
energy meter chip for measurement accuracy and overall system use.
The board is pre-programmed with a demo program in the flash memory of the 71M6533 IC. This embedded
application is developed to exercise all low-level function calls to directly manage the peripherals, flash
programming, and CPU (clock, timing, power savings, etc.).
The 71M6533 IC on the demo board is pre-programmed with default calibration factors. Since current sensors
are not part of the Demo Kit, the demo board is tested but not calibrated at the factory.
1.2 SAFETY AND ESD NOTES
Connecting live voltages to the demo board system will result in potentially hazardous voltages on the demo
board.
THE DEMO SYSTEM IS ESD SENSITIVE! ESD PRECAUTIONS SHOULD BE TAKEN
WHEN HANDLING THE DEMO BOARD!
EXTREME CAUTION SHOULD BE TAKEN WHEN HANDLING THE DEMO BOARD
ONCE IT IS CONNECTED TO LIVE VOLTAGES!
1.3 DEMO KIT CONTENTS
71M6533-DB Demo Board with 71M6533F IC and Pre-Loaded Demo Program
USB-to-Serial Adapter
5VDC/1000mA Universal Wall Transformer with 2.5mm Plug (Switchcraft 712A Compatible)
USB Cable
1.4 DEMO BOARD VERSIONS
Currently, only the following version of the Demo Board is available:
71M6533-DB Demo Board (REV 3.0, standard)
Page: 7 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
Windows and Windows XP are registered trademarks of Microsoft Corp.
1.5 COMPATIBILITY
This manual applies to the following hardware and software revisions:
71M6533 or 71M6533H chip revision A03
Demo Kit firmware revision 4.p6q or later
71M6533-DB Demo Board REV 3.0
1.6 SUGGESTED EQUIPMENT NOT INCLUDED
For functional demonstration:
PC with Microsoft Windows operating systems: Windows XP, Windows ME, or Windows 2000, equipped
with RS232 port (COM port) via DB9 connector
For software development (MPU code):
Signum ICE (In Circuit Emulator): ADM-51
http://www.signum.com
Keil 8051 “C” Compiler kit: CA51
www.keil.com/c51/ca51kit.htm, www.keil.com/product/sales
1.7 DEMO BOARD TEST SETUP
The 71M6533-DB Demo Board block diagram is shown in Figure 1-1. The configuration consists of a standalone (round) meter Demo Board and an optional Debug Board. The Demo Board contains all circuits
necessary for operation as a meter, including display, calibration LEDs, and internal power supply. The optional
Debug Board, uses a separate power supply, and is optically isolated from the Demo Board. It interfaces to a
PC through a 9 pin serial port connector. For serial communication between the PC and the 71M6533, the
Debug Board needs to be plugged with its connector J3 into connector J2 of the Demo Board.
The USB-Serial Adapter allows communication between the 71M6533-DB Demo Board and a PC via its USB
port.
Connections to the external signals to be measured, i.e. scaled AC voltages and current signals derived from
shunt resistors or from current transformers, are provided on the rear side of the demo board.
Caution: It is recommended to set up the demo board with no live AC voltage
connected, and to connect live AC voltages only after the user is familiar with
the demo system.
All input signals are referenced to the V3P3A (3.3V power supply to the chip).
Page: 8 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
DEMONSTRATION METER
IA
IB
IC
VC
VB
NEUTRAL
IAP
IBP
ICP
V3P3A
VC
VB
VA
3.3v
VA
GND
V3P3
GND
5V DC
EEPROM
ICE Connector
DIO56
DIO57
DIO58
TX
RX
DB9
to PC
COM Port
J5
68 Pin Connector
to NI PCI-6534
DIO Board
6533
Single Chip
Meter
TMUXOUT
CKTEST
3.3V LCD
DIO4
DIO5
ID P
INEUTRAL
External Current
Transformers
IAN
IBN
ICN
V3P3SYS
Wh
VARh
DIO6/WPULSE
DIO7/RPULSE
PULSE OUTPUTS
DIO9/YPULSE
DIO8/XPULSE
V3P3SYS
V3P3D
VBAT
PB
battery
(optional)
JP8
PB
On-board
components
powered by
V3P3D
OPTO
OPTO
OPTO
OPTO
OPTO
5V DC
V5_DBG
GND_DBG
V5_DBG
V5_DBG
RS-232
INTERFACE
GND_DBG
V5_DBG
OPTO
OPTO
FPGA
04/25/2008
V5_NI
CE HEARTBEAT (1Hz)
MPU HEARTBEAT (5Hz)
DEBUG BOARD (OPTIONAL)
RTM INTERFACE
JP21
J2
N/C
N/C
4
15, 16
13, 14
6
6
8
12
10
3
1
2
5, 7,
9, 11
GND
V3P3SYS
JP1
ID N
Figure 1-1: Block Diagram for the 71M6533-DB Demo Board with Debug Board
1.7.1 SETUP WITH USB-TO-SERIAL ADAPTER
The USB-to-Serial Adapter shipped with Demo Kits starting in June 2011 provides a connection to the Demo
Board via USB. The USB-to-Serial Adapter is plugged into connector J2 of the DB6533 as shown in Figure 1-2.
The PC should be running HyperTerminal or a similar serial interface program. A suitable driver, e.g. the FTDI
CDM Driver Package, must be installed on the PC to enable the USB port to be mapped as a virtual COM port.
The driver can be found on the FTDI web site (http://www.ftdichip.com/Drivers/D2XX.htm).
The USB-to-Serial Adapter is self-powered via the USB port on the PC.
Page: 9 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
H E L L 0
3. 0. 0 0
1
3. W h
Figure 1-2: DB6534T14A3 Demo Board with USB-to-Serial Adapter
1.7.2 POWER SUPPLY SETUP
There are several choices for the meter power supply:
Internal (using phase A of the AC line voltage). The internal power supply is only suitable when the phase A
voltage exceeds 220V RMS. A jumper needs to be installed across JP1 on the bottom of the board.
External 5VDC connector (J1) on the Demo Board.
1.7.3 CHECKING OPERATION
A few seconds after power up, the LCD display on the Demo Board should display this brief greeting:
The “HELLO” message should be followed by the display of accumulated energy:
The Wh display should be followed by the text “Wh”, as shown below:
The decimal dot in the rightmost segment will be blinking, indicating activity of the MPU inside the 71M6533.
The Demo Code allows cycling of the display using the PB button. By briefly pressing this button, the next
available parameter from Table 1-1 is selected. This makes it easy to navigate various displays for Demo
Boards without having to use the command line interface (CLI).
Page: 10 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
Step
Display in
left-most
digit(s)
Text
display
Correspon-
ding CLI
command
Displayed Parameter
1
1
Delt C
M1
Temperature difference from calibration temperature.
Displayed in 0.1°C
2
2
HZ
M2
Frequency at the VA_IN input [Hz]
3
3
Wh
M3
Accumulated real energy [Wh]. The default display setting
after power-up or reset.
4
4
Wh
M4
Accumulated exported real energy [Wh].
5
5
VARh
M5
Accumulated reactive energy [VARh].
6
6
VARh
M6
Accumulated exported reactive energy [VARh].
7
7
VAh
M7
Accumulated apparent energy [VAh].
8
8
HOURS
M8
Elapsed time
9
9
TIME
M9
Time of day (hh.mm.ss)
10
--
DATE
M10
Date (yyyy.mm.dd)
11
11
PF
M11
Power factor
12
12
--
M12
V/V phase angle [degrees]
13
13
EDGES
M13
Zero crossings of the mains voltage
14
14
PULSES
M14
Pulse counter
15
15
A
M15
RMS current
16
16
V
M16
RMS voltage
17
17
BAT V
M17
Battery voltage
1.7.4 SERIAL CONNECTION SETUP
After connecting the DB9 serial port to a PC, start the HyperTerminal application and create a session using the
following parameters:
Port Speed: 9600 bd or 300bd (see below)
Data Bits: 8
Parity: None
Stop Bits: 1
Flow Control: XON/XOFF
See section 3.1 for proper selection of the operation mode when main power is removed:
A jumper across pins 2-3 (VBAT-GND) of JP16 indicates that no external battery is available. The IC
will stay in brownout mode when the system power is down and it will communicate at 9600bd.
A jumper across pins 1-2 (BATMODE-VBAT) indicates that an external battery is available. The IC will
be able to transition from brownout mode to sleep and LCD modes when the system power is down
and it will communicate at 300bd.
HyperTerminal can be found by selecting Programs Accessories Communications from the Windows start
menu. The connection parameters are configured by selecting File Properties and then by pressing the
Page: 11 of 75 ` REV 3
Table 1-1: Selectable Display Options
71M6533-DB Demo Board User’s Manual
Configure button. Port speed and flow control are configured under the General tab (Figure 1-4, left), bit settings
are configured by pressing the Configure button (Figure 1-4, right), as shown below. A setup file (file name
“Demo Board Connection.ht”) for HyperTerminal that can be loaded with File Open is also provided with the
tools and utilities.
Port parameters can only be adjusted when the connection is not active. The disconnect
button, as shown in Figure 1-3 must be clicked in order to disconnect the port.
Figure 1-3: Hyperterminal Sample Window with Disconnect Button (Arrow)
Figure 1-4: Port Speed and Handshake Setup (left) and Port Bit setup (right)
Once, the connection to the demo board is established, press <CR> and the command prompt, >, should
appear. Type >? to see the Demo Code help menu. Type >i to verify the demo code revision.
Page: 12 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
1.8 USING THE DEMO BOARD
The 71M6533-DB Demo Board is a ready-to -use meter prepared for use with external current transformers
(CTs).
Using the Demo Board involves communicating with the Demo Code via the command line interface (CLI). The
CLI allows all sorts of manipulations to the metering parameters, access to the EEPROM, initiation of auto-cal
sequences, selection of the displayed parameters, changing calibration factors and many more operations.
Before evaluating the 71M6533 on the Demo Board, users should get familiar with the commands and
responses of the CLI. A complete description of the CLI is provided in section 1.8.1.
1.8.1 SERIAL COMMAND LANGUAGE
The Demo Code residing in the flash memory of the 71M6533 provides a convenient way of examining and
modifying key meter parameters. Once the Demo Board is connected to a PC or terminal per the instructions
given in Section Error! Reference source not found. and 1.7.4, typing ‘?’ will bring up the list of commands
shown in Figure 1-5.
Figure 1-5: Command Line Help Display
The tables in this chapter describe the commands in detail.
Page: 13 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
?
HELP
Comment
Description:
Command help available for each of the options below.
Command
combinations:
?
Command line interpreter help menu.
?]
Display help on access CE data RAM
?)
Display help on access MPU RAM
?,
Display help on repeat last command
?/
Display help on ignore rest of line
?C
Display help on compute engine control.
?CL
Display help on calibration.
?EE
Display help on EEPROM control
?ER
Display help on error recording
?I
Display help on information message
?M
Display help on meter display control
?MR
Display help on meter RMS display control
?R
Display help on SFR control
?RT
Display help on RTC control
?T
Display help on trim control
?W
Display help on the wait/reset command
?Z
Display help on reset
Examples:
??
Display the command line interpreter help menu.
?C
Displays compute engine control help.
]
CE DATA ACCESS
Comment
Description:
Allows user to read from and write to CE data space.
Usage:
] [Starting CE Data Address] [option]…[option]
Command
combinations:
]A???
Read consecutive 16-bit words in Decimal, starting at
address A
]A$$$
Read consecutive 16-bit words in Hex, starting at address A
]A=n=n
Write consecutive memory values, starting at address A
]U
Update default version of CE Data in flash memory
Example:
]40$$$
Reads CE data words 0x40, 0x41 and 0x42.
]7E=12345678=9876ABCD
Writes two words starting @ 0x7E
Commands to Display Help on the CLI Commands:
Commands for CE Data Access:
All CE data words are in 4-byte (32-bit) format. Typing ]A? will access the 32-bit word located at the byte
address 0x1000 + 4 * A = 0x1028.
Page: 14 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
)
MPU DATA ACCESS
Comment
Description:
Allows user to read from and write to MPU data space.
Usage:
) [Starting MPU Data Address] [option]…[option]
Command
combinations:
)A???
Read three consecutive 32-bit words in Decimal, starting at
address A
)A$$$
Read three consecutive 32-bit words in Hex, starting at
address A
)A=n=m
Write the values n and m to two consecutive addresses
starting at address A
?)
Display useful RAM addresses.
Example:
)08$$$$
Reads data words 0x08, 0x0C, 0x10, 0x14
)04=12345678=9876ABCD
Writes two words starting @ 0x04
R
DIO AND SFR CONTROL
Comment
Description:
Allows the user to read from and write to DIO RAM and special function registers (SFRs).
Usage:
R [option] [register] … [option]
Command
combinations:
RIx…
Select I/O RAM location x (0x2000 offset is automatically
added)
Rx…
Select internal SFR at address x
Ra???...
Read consecutive SFR registers in Decimal, starting at
address a
Ra$$$...
Read consecutive registers in Hex, starting at address a
Ra=n=m…
Set values of consecutive registers to n and m starting at
address a
Example:
RI2$$$
Read DIO RAM registers 2, 3, and 4 in Hex.
Commands for MPU/XDATA Access:
MPU or XDATA space is the address range for the MPU XRAM (0x0000 to 0xFFF). All MPU data words are in 4-byte (32-bit)
format. Typing ]A? will access the 32-bit word located at the byte address 4 * A = 0x28. The energy accumulation registers of
the Demo Code can be accessed by typing two Dollar signs (“$$”), typing question marks will display negative decimal values
if the most significant bit is set.
Commands for DIO RAM (Configuration RAM) and SFR Control:
DIO or Configuration RAM space is the address range 0x2000 to 0x20FF. This RAM contains registers used for configuring
basic hardware and functional properties of the 71M6533 and is organized in bytes (8 bits). The 0x2000 offset is automatically
added when the command RI is typed.
The SFRs (special function registers) are located in internal RAM of the 80515 core, starting at address 0x80.
Page: 15 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
EE
EEPROM CONTROL
Comment
Description:
Allows user to enable read and write to EEPROM.
Usage:
EE [option] [arguments]
Command
combinations:
EECn
EEPROM Access (1 Enable, 0 Disable)
EERa.b
Read EEPROM at address 'a' for 'b' bytes.
EESabc..xyz
Write characters to buffer (sets Write length)
EETa
Transmit buffer to EEPROM at address 'a'.
EEWa.b...z
Write values to buffer
CLS
Saves calibration to EEPROM
Example:
EEShello
EET$0210
Writes 'hello' to buffer, then transmits buffer to EEPROM
starting at address 0x210.
C
COMPUTE ENGINE
CONTROL
Comment
Description:
Allows the user to enable and configure the compute engine.
Usage:
C [option] [argument]
Command
combinations:
CEn
Compute Engine Enable (1 Enable,
0 Disable)
CTn
Select input n for TMUX output pin. n is interpreted as a
decimal number.
CREn
RTM output control (1 Enable, 0 Disable)
CRSa.b.c.d
Selects CE addresses for RTM output
Example:
CE0
Disables CE, followed by “CE OFF” display on LCD. The
Demo Code will reset if the WD timer is enabled.
CT3
Selects the VBIAS signal for the TMUX output pin
Commands for EEPROM Control:
Due to buffer size restrictions, the maximum number of bytes handled by the EEPROM command is 0x40.
Auxiliary Commands:
Typing a comma (“,”) repeats the command issued from the previous command line. This is very helpful when
examining the value at a certain address over time, such as the CE DRAM address for the temperature (0x40).
The slash (“/”) is useful to separate comments from commands when sending macro text files via the serial
interface. All characters in a line after the slash are ignored.
Commands controlling the CE, TMUX and the RTM:
Page: 16 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
CL
AUTO-CALIBRATION
CONTROL
Comment
Description:
Allows the user to initiate auto-calibration and to store calibration values.
Usage:
CL [option]
Command
combinations:
CLB
Begin auto-calibration. Prior to auto-calibration, the calibration
coefficients are automatically restored from flash memory.
CLS
Save calibration coefficients to EEPROM starting at address
0x0004
CLC
Use machine-readable calibration protocol
CLR
Restore calibration coefficients from EEPROM
CLD
Restore coefficients from flash memory
Example:
CLB
Starts auto-calibration and saves data automatically.
CP
PULSE-COUNT CONTROL
Comment
Description:
Allows the user to control the pulse count functions.
Usage:
CP [option]
Command
combinations:
CPA
Start pulse counting for time period defined with the CPD
command. Pulse counts will display with commands M15.2,
M16.2
CPC
Clear the absolute pulse count displays (shown with
commands M15.1, M16.1)
CPDn
Set time window for pulse counters to n seconds, n is interpreted as a decimal number.
Example:
CPD60
Set time window to 60 seconds.
I
INFORMATION MESSAGES
Comment
Description:
Allows user to read information messages.
Usage:
I
Displays complete version information
Commands controlling the Auto-Calibration Function:
Before starting the auto-calibration process, target values for voltage, duration and current must be entered in
MPU RAM (see section 1.9.5) and the target voltage and current must be applied constantly during calibration.
Calibration factors can be saved to EEPROM using the CLS command.
Commands controlling the Pulse Counter Function
Pulse counts accumulated over a time window defined by the CPD command will be displayed by M14 after the
defined time has expired.
M14 will display the absolute pulse count for the W and VAR outputs. These displays are reset to zero with the
CPC command (or the XRAM write )1=2).
Commands for Identification and Information:
The I command is mainly used to identify the revisions of Demo Code and the contained CE code.
Page: 17 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
MR
METER RMS DISPLAY
CONTROL (LCD)
Comment
Description:
Allows user to select meter RMS display for voltage or current.
Usage:
MR [option]. [option]
Command
combinations:
MR1. [phase]
Displays instantaneous RMS current
MR2. [phase]
Displays instantaneous RMS voltage
Example:
MR1.3
Displays phase C RMS current.
PS
POWER SAVE MODE
Comment
Description:
Enters power save mode
Disables CE, ADC, CKOUT, ECK, RTM, SSI, TMUX VREF,
and serial port, sets MPU clock to 38.4KHz.
Usage:
PS
RT
REAL TIME CLOCK
CONTROL
Comment
Description:
Allows the user to read and set the real time clock.
Usage:
RT [option] [value] … [value]
Command
combinations:
RTDy.m.d.w: Day of week
(year, month, day, weekday [1 = Sunday]). If the weekday is
omitted it is set automatically.
RTR
Read Real Time Clock.
RTTh.m.s
Time of day: (hr, min, sec).
RTAs.t
Real Time Adjust: (start, trim). Allows trimming of the RTC.
If s > 0, the speed of the clock will be adjusted by ‘t’ parts per
billion (PPB). If the CE is on, the value entered with 't' will be
changing with temperature, based on Y_CAL, Y_CALC and
Y_CALC2.
Example:
RTD05.03.17.5
Programs the RTC to Thursday, 3/17/2005
RTA1.+1234
Speeds up the RTC by 1234 PPB.
Commands for Controlling the RMS Values Shown on the LCD Display:
Phase 4 is the measured neutral current.
No error message is issued when an invalid parameter is entered, e.g. MR1.8.
Commands for Controlling the MPU Power Save Mode:
Return to normal mode is achieved by resetting the MPU (Z command).
Commands for Controlling the RTC:
The “Military Time Format” is used for the RTC, i.e. 15:00 is 3:00 PM.
Page: 18 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
T
TRIM CONTROL
Comment
Description:
Allows user to read trim and fuse values.
Usage:
T [option]
Command
combinations:
T4
Read fuse 4 (TRIMM).
T5
Read fuse 5 (TRIMBGA)
T6
Read fuse 6 (TRIMBGB).
Example:
T4
Reads the TRIMM fuse.
W
RESET
Comment
Description:
Watchdog control
Usage:
W
Halts the Demo Code program, thus suppressing the triggering of the hardware watchdog timer. This will cause a reset, if
the watchdog timer is enabled.
W
RESET
Comment
Description:
Control of Sleep and LCD Modes
when in Brownout Mode
These commands are accepted only when the 71M6533 is in
Brownout mode.
Commands:
BL
Takes the 71M6533 to LCD Mode.
BS
Takes the 71M6533 to Sleep Mode.
BWSn
Takes the 71M6533 to Sleep Mode and sets the wake-up
timer to n seconds.
BWMn
Takes the 71M6533 to Sleep Mode and sets the wake-up
timer to n minutes.
Commands for Accessing the Trim Control Registers:
These commands are only accessible for the 71M6533H (0.1%) parts. When used on a 71M6533 (0.5%) part,
the results will be displayed as zero.
Reset Commands:
Battery-Mode Commands:
Page: 19 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
M
METER DISPLAY
CONTROL (LCD)
Comment
Description:
Allows user to select internal variables to be displayed.
Usage:
M [option]. [option]
Command
combinations:
M
Wh Total Consumption (display wraps around at 999.999)
M0
Wh Total Consumption (display wraps around at 999.999)
M1
Temperature (C° delta from nominal)
M2
Frequency (Hz)
M3. [phase]
Wh Total Consumption (display wraps around at 999.999)
M4. [phase]
Wh Total Inverse Consumption (display wraps around at 999.999)
M5. [phase]
VARh Total Consumption (display wraps around at 999.999)
M6. [phase]
VARh Total Inverse Consumption (display wraps around at 999.999)
M7. [phase]
VAh Total (display wraps around at 999.999)
M8
Operating Time (in hours)
M9
Real Time Clock
M10
Calendar Date
M11. [phase]
Power factor
M13
Mains edge count for the last accumulation interval
M13.1
Main edge count (accumulated) – zero transitions of the input signal
M13.2
Main edge count for the last accumulation interval
M14.1
Absolute count for Wh pulses. Reset with CPC command.
M14.2
Absolute count for VARh pulses. Reset with CPC command.
M15.[phase]
I RMS display
M16.[phase]
V RMS display
Example:
M3.3
Displays Wh total consumption of phase C.
M5.0
Displays VARh total consumption for all phases.
Commands for Controlling the Metering Values Shown on the LCD Display:
Displays for total consumption wrap around at 999.999Wh (or VARh, VAh) due to the limited number of
available display digits. Internal registers (counters) of the Demo Code are 64 bits wide and do not wrap
around.
When entering the phase parameter, use 1 for phase A, 2 for phase B, 3 for phase C, and 0 or blank for all
phases.
Page: 20 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
1.8.2 USING THE DEMO BOARD FOR ENERGY MEASUREMENTS
The 71M6533-DB Demo Board was designed for use with current transformers (CT).
The Demo Board may immediately be used with current transformers having 2,000:1 winding ratio and is
programmed for a Kh factor of 3.2 and (see Section 1.8.4 for adjusting the Demo Board for transformers with
different turns ratio).
Once, voltage is applied and load current is flowing, the red LED D5 will flash each time an energy sum of 3.2
Wh is collected. The LCD display will show the accumulated energy in Wh when set to display mode 3
(command >M3 via the serial interface).
Similarly, the red LED D6 will flash each time an energy sum of 3.2 VARh is collected. The LCD display will
show the accumulated energy in VARh when set to display mode 5 (command >M5 via the serial interface).
1.8.3 ADJUSTING THE KH FACTOR FOR THE DEMO BOARD
The 71M6533-DB Demo Board is shipped with a pre-programmed scaling factor Kh of 3.2, i.e. 3.2Wh per pulse.
In order to be used with a calibrated load or a meter calibration system, the board should be connected to the
AC power source using the spade terminals on the bottom of the board. The current transformers should be
connected to the dual-pin headers on the bottom of the board.
The Kh value can be derived by reading the values for IMAX and VMAX (i.e. the RMS current and voltage
values that correspond to the 250mV maximum input signal to the IC), and inserting them in the following
equation for Kh:
Kh = IMAX * VMAX * 66.1782 / (In_8 * WRATE * N
The small deviation between the adjusted Kh of 3.19902 and the ideal Kh of 3.2 is covered by calibration. The
default values used for the 71M6533-DB Demo Board are:
WRATE: 683
IMAX: 208
VMAX: 600
In_8: 1 (controlled by IA_SHUNT = 0)
N
: 2520
ACC
X: 6
Explanation of factors used in the Kh calculation:
WRATE: The factor input by the user to determine Kh
IMAX: The current input scaling factor, i.e. the input current generating 177mVrms at the IA/IB/IC
input pins of the 71M6533. 177mV rms is equivalent to 250mV peak.
VMAX: The voltage input scaling factor, i.e. the voltage generating 177mVrms at the VA/VB/VC input
pins of the 71M6533
In_8: The setting for the additional ADC gain (8 or 1) determined by the CE register IA_SHUNT
N
: The number of samples per accumulation interval, i.e. PRE_SAMPS *SUM_CYCLES
ACC
X: The pulse rate control factor determined by the CE registers PULSE_SLOW and PULSE_FAST
Almost any desired Kh factor can be selected for the Demo Board by resolving the formula for WRATE:
WRATE = (IMAX * VMAX * 66.1782) / (Kh * In_8 * N
For the Kh of 3.2Wh, the value 171 (decimal) should be entered for WRATE at location 21 (using the CLI
command >]21=+171).
* X) = 3.19902 Wh/pulse.
ACC
* X)
ACC
1.8.4 ADJUSTING THE DEMO BOARDS TO DIFFERENT CURRENT TRANSFORMERS
The Demo Board is prepared for use with 2000:1 current transformers (CTs). This means that for the
unmodified Demo Board, 208A on the primary side at 2000:1 ratio result in 104mA on the secondary side,
causing 177mV at the 1.7 resistor pairs R24/R25, R36/R37, R56/R57 (2 x 3.4 in parallel).
Page: 21 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
In general, when IMAX is applied to the primary side of the CT, the voltage Vin at the IA, IB, or IC input of the
71M6533 IC is determined by the following formula:
V
= R * I = R * IMAX/N
in
where N = transformer winding ratio, R = resistor on the secondary side
If, for example, IMAX = 208A are applied to a CT with a 2500:1 ratio, only 83.2mA will be generated on the secondary side, causing only 141mV. The steps required to adapt a 71M6533-DB Demo Board to a transformer
with a winding ratio of 2500:1 are outlined below:
1) The formula Rx = 177mV/(IMAX/N) is applied to calculate the new resistor Rx. We calculate Rx to 2.115
2) Changing the resistors R24/R25, R106/R107 to a combined resistance of 2.115 (for each pair) will
cause the desired voltage drop of 177mV appearing at the IA, IB, or IC inputs of the 71M6533 IC.
3) WRATE should be adjusted to achieve the desired Kh factor, as described in 1.8.3.
Simply scaling IMAX is not recommended, since peak voltages at the 71M6533 inputs should always be in the
range of 0 through ±250mV (equivalent to 177mV rms). If a CT with a much lower winding ratio than 1:2,000 is
used, higher secondary currents will result, causing excessive voltages at the 71M6533 inputs. Conversely, CTs
with much higher ratio will tend to decrease the useable signal voltage range at the 71M6533 inputs and may
thus decrease resolution.
1.8.5 ADJUSTING THE DEMO BOARDS TO DIFFERENT VOLTAGE DIVIDERS
The 71M6533-DB Demo Board comes equipped with its own network of resistor dividers for voltage
measurement mounted on the PCB. The resistor values (for the 71M6533-DB Demo Board) are 2.5477M
(R15-R21, R26-R31 combined) and 750 (R32), resulting in a ratio of 1:3,393.933. This means that VMAX
equals 176.78mV*3,393.933 = 600V. A large value for VMAX has been selected in order to have headroom for
over-voltages. This choice need not be of concern, since the ADC in the 71M6533 has enough resolution, even
when operating at 120Vrms or 240Vrms.
If a different set of voltage dividers or an external voltage transformer (potential transformer) is to be used,
scaling techniques similar to those applied for the current transformer should be used.
In the following example we assume that the line voltage is not applied to the resistor divider for VA formed by
R15-R21, R26-R31, and R32, but to a voltage transformer with a ratio N of 20:1, followed by a simple resistor
divider. We also assume that we want to maintain the value for VMAX at 600V to provide headroom for large
voltage excursions.
When applying VMAX at the primary side of the transformer, the secondary voltage Vs is:
Vs = VMAX / N
Vs is scaled by the resistor divider ratio RR. When the input voltage to the voltage channel of the 71M6533 is the
desired 177mV, Vs is then given by:
Vs = RR * 177mV
Resolving for RR, we get:
RR = (VMAX / N) / 177mV = (600V / 30) / 177mV = 170.45
This divider ratio can be implemented, for example, with a combination of one 16.95k and one 100 resistor.
If potential transformers (PTs) are used instead of resistor dividers, phase shifts will be introduced that will re-
quire negative phase angle compensation. Standard Demo Code accepts negative calibration factors for phase.
Page: 22 of 75 ` REV 3
71M6533-DB Demo Board User’s Manual
Constant
CE
Address
(hex)
Description
CAL_VA
CAL_VB
CAL_VC
0x11
0x13
0x15
Adjusts the gain of the voltage channels. +16384 is the typical value. The
gain is directly proportional to the CAL parameter. Allowed range is 0 to
32767. If the gain is 1% slow, CAL should be increased by 1%.
CAL_IA
CAL_IB
CAL_IC
0x10
0x12
0x14
Adjusts the gain of the current channels. +16384 is the typical value. The
gain is directly proportional to the CAL parameter. Allowed range is 0 to
32767. If the gain is 1% slow, CAL should be increased by 1%.
PHADJ_A
PHADJ_B
PHADJ_C
0x18
0x19
0x1A
This constant controls the CT phase compensation. No compensation
occurs when PHADJ=0. As PHADJ is increased, more compensation is
introduced.
1.9 CALIBRATION PARAMETERS
1.9.1 GENERAL CALIBRATION PROCEDURE
Any calibration method can be used with the 71M6533 chips. This Demo Board User’s Manual presents
calibration methods with three or five measurements as recommended methods, because they work with most
manual calibration systems based on counting "pulses" (emitted by LEDs on the meter).
Naturally, a meter in mass production will be equipped with special calibration code offering capabilities beyond
those of the Demo Code. It is basically possible to calibrate using voltage and current readings, with or without
pulses involved. For this purpose, the MPU Demo Code can be modified to display averaged voltage and
current values (as opposed to momentary values). Also, automated calibration equipment can communicate
with the Demo Boards via the serial interface and extract voltage and current readings. This is possible even
with the unmodified Demo Code.
Complete calibration procedures are given in section 2.2 of this manual.
Regardless of the calibration procedure used, parameters (calibration factors) will result that will have to be
applied to the 71M6533 chip in order to make the chip apply the modified gains and phase shifts necessary for
accurate operation. Table 1-2 shows the names of the calibration factors, their function, and their location in the
CE RAM.
Again, the command line interface can be used to store the calibration factors in their respective CE RAM
addresses. For example, the command
>]10=+16302
stores the decimal value 16302 in the CE RAM location controlling the gain of the current channel (CAL_IA) for
phase A.
The command
>]11=4005
stores the hexadecimal value 0x4005 (decimal 16389) in the CE RAM location controlling the gain of the
voltage channel for phase A (CAL_VA).
Table 1-2: CE RAM Locations for Calibration Constants
Page: 23 of 75 ` REV 3
Loading...