Landis+Gyr Cashpower Gem Lite User manual

Cashpower Prepayment Metering
Cashpower Gem Lite
User Guide
Document version: 0.10
Date: 14/06/2011
Corresponds to
Filename: User Manual Gem Lite.docx
Landis+Gyr (Pty) Ltd
Electricity Prepayment Meters
Residential

2/27 Review Abbreviations
© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
Revision history
Version
Date
Comments
0.0
11/12/2009
Original document
0.1
14/06/2011
Corrections to section 4.4.1 and 4.4.5
Copyright © 2005-2009, Landis+Gyr. All rights reserved. Subject to change without notice.
Landis+Gyr (Pty) Ltd
2 Slate Avenue, N1 Business Park
Old Johannesburg Road, Kosmosdal Ext.7
Gauteng, South Africa
Phone: [phone]
www.landisgyr.com/za

Abbreviations Review 3/27
Cashpower Gem Lite –User Guide © Landis+Gyr (Pty) Ltd
Table of Contents
1Abbreviations __________________________________________________________ 5
2Front Panel Layout ______________________________________________________ 6
2.1 Keypad _____________________________________________________________ 6
2.2 Liquid Crystal Display (LCD) _____________________________________________ 6
2.3 Rate of Consumption Indicator (Rate LED) __________________________________ 6
3Liquid Crystal Display (LCD) ______________________________________________ 7
3.1 General _____________________________________________________________ 7
3.2 LCD Layout (what the icons mean) ________________________________________ 7
3.2.1 Legend____________________________________________________________ 7
3.3 Typical Operational Displays _____________________________________________ 8
3.4 Happy and Sad Faces __________________________________________________ 8
3.5 Latching Relay Status Indicators __________________________________________ 9
3.6 Information Mode Indicator ______________________________________________ 9
3.7 Power Indicator (kWh)__________________________________________________ 9
3.8 Power (W) Indicator____________________________________________________ 9
3.9 Remaining Credit Indicator ______________________________________________ 9
3.10 Alarm Indicator ______________________________________________________ 10
4Meter Operation________________________________________________________ 11
4.1 General ____________________________________________________________ 11
4.2 LCD Indications during Normal Operation __________________________________ 11
4.3 Entering Prepayment Tokens via the Keypad _______________________________ 11
4.3.1 Happy & Sad face indications _________________________________________ 12
4.4 Token Processing ____________________________________________________ 12
4.4.1 Incomplete Token __________________________________________________ 12
4.4.2 Complete Token ___________________________________________________ 13
4.4.3 Token Accepted____________________________________________________ 13
4.4.4 Token Accepted as a Valid Key Change Number __________________________ 13
4.4.5 Incorrect Token ____________________________________________________ 13
4.4.6 Duplicate Token____________________________________________________ 13
4.4.7 Expired Token _____________________________________________________ 13
4.4.8 Token Overflow Rejection ____________________________________________ 13
4.5 Token Decryption and Processing ________________________________________ 14
4.5.1 Electricity Credit Token ______________________________________________ 14
4.5.2 Set 1st Dispenser Key Token__________________________________________ 14
4.5.3 Set 2nd Dispenser Key Token _________________________________________ 14
4.5.4 Clear Tamper Token ________________________________________________ 14
4.5.5 Set Power Limit Token_______________________________________________ 14
4.5.6 Set Credit Alarm Levels Token (Proprietary Token)_________________________ 14
4.5.7 Clear Credit Token__________________________________________________ 15
4.5.8 Initiate Dispenser Test Token (Meter Non-Specific Token) ___________________ 15
4.5.9 Commissioning Token (Non Meter-Specific, Proprietary Token) _______________ 15
4.5.10 Commissioning Token (Meter-Specific, Proprietary Token) ___________________ 15

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© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
4.5.11 Decommissioning Token (Meter-Specific, Proprietary Token) _________________ 15
4.5.12 Set Options Register (Meter-Specific, Proprietary Token) ____________________16
4.5.13 Commissioning and Decommissioning the Meter___________________________ 16
4.6 Power Limiting _______________________________________________________16
4.7 Automatic/Manual Load Reconnection_____________________________________17
4.8 Disconnect on Power Failure ____________________________________________17
4.9 Anti-tamper Features __________________________________________________ 18
4.9.1 General __________________________________________________________ 18
4.9.2 Anti-Tamper Switch _________________________________________________18
4.9.3 Reverse Energy Detection ____________________________________________18
4.9.4 Magnetic Tamper Detection ___________________________________________ 18
4.9.5 Resetting a Tamper Condition _________________________________________18
4.10 Virtual Token Carrier (VTC) Interface______________________________________19
5Information Functions ___________________________________________________ 20
5.1 Information Register Functions___________________________________________20
5.1.1 Meter Number (Register 000)__________________________________________ 21
5.1.2 Instantaneous Power (Register 001) ____________________________________21
5.1.3 Current Credit Register (Register 002) ___________________________________21
5.1.4 Total Units Counter (Register 003)______________________________________22
5.1.5 Accumulated Credit Register (Register 005)_______________________________22
5.1.6 Current 30-Day Consumption (Register 008) ______________________________ 22
5.1.7 Previous 30-Day Consumption (Register 009) _____________________________22
5.1.8 Low Credit Level (Register 012)________________________________________ 22
5.1.9 High Credit Level (Register 013) _______________________________________ 22
5.1.10 Power Limit Level (Register 014) _______________________________________22
5.1.11 How to use the State & Options Registers ________________________________22
5.1.12 Meter State Register UPPER (Register 030) ______________________________23
5.1.13 Meter State Register LOWER (Register 031) ______________________________23
5.1.14 Fixed Option Register (Register 033) ____________________________________ 24
5.1.15 Changeable Option Register (Register 035)_______________________________ 24
5.1.16 Volatile Meter State –Upper (Register 036)_______________________________ 25
5.1.17 Volatile Meter State –Lower (Register 037)_______________________________25
5.1.18 Software Version Number (Register 048)_________________________________26
5.1.19 Power-Fail Counter (Register 050)______________________________________26
5.1.20 TN and ID Number of Last CTN Entered (Register 054)______________________26
5.1.21 ID Number of Last CTN Entered (Register 055) ____________________________ 26
5.1.22 Value of Last CTN Entered (Register 056) ________________________________26
5.1.23 Key Revision and Key Type (Register 057) _______________________________ 26
5.1.24 Tariff Index (Register 058) ____________________________________________ 26
5.1.25 Current Credit Register - 10Wh Resolution (Register 059) ____________________26
5.1.26 SGC Register (Register 060) __________________________________________26
5.1.27 Total Units Counter (10 Wh Resolution) (Register 061) ______________________27
5.1.28 Last fifty 20 digit numbers entered into the meter___________________________27
5.1.29 Customer Information Mode___________________________________________27

Abbreviations Review 5/27
Cashpower Gem Lite –User Guide © Landis+Gyr (Pty) Ltd
1 Abbreviations
LCD Liquid Crystal Display
LED Light Emitting Diode
STS Standard Transfer Specification (open prepayment standard)
CTN Credit Transfer Number
TN Transfer Number
KRN Key Revision Number
TI Tariff Index

6/27 Review Front Panel Layout
© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
2 Front Panel Layout
Figure 1: The Cashpower Gem Lite Prepayment Meter
2.1 Keypad
The 12-key keypad enables the entry of tokens and the accessing of various information functions.
Key-presses are acknowledged with an audible beep.
2.2 Liquid Crystal Display (LCD)
The LCD normally displays remaining credit but also displays the scrolling in of keypad entries and
viewing of various information functions.
2.3 Rate of Consumption Indicator (Rate LED)
A red rate of consumption LED provides a visual indication of instantaneous power consumption.
Its main function is to give a visible indication of energy usage i.e. a fast
flash rate signifies high usage. The rate LED is also a reference output and
can be used to verify the metrological accuracy.
LCD Display
The display consists of three
functional blocks, a 7 digit
numerical display, various
pictograms (such as credit
wedge and alarm indicator) and
pointers, which point to
pictograms on the membrane
Back-space key
Allows back space to correct
number entered
Information Key
Entering information mode enables
access to the meter parameters,
refer to meter register codes in this
document
Rate of Consumption
Indicator
This displays the rate of electricity
consumption. A fast flash indicates
high usage while a slow flash
indicates low usage
Keypad
Used for entering the
prepayment token as well as
accessing various meter
parameters
Sealing Screw
Use standard utility sealing wires
Terminal cover
Normally supplied with a long
terminal cover
Display Pictograms
Language independent
pictograms below the LCD
display

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3 Liquid Crystal Display (LCD)
3.1 General
The LCD is designed to give a clear and unambiguous visual indication of the important meter
functions by means of language-independent pictograms. The LCD has three functional blocks: a
numerical display for displaying various values such as remaining credit and power limit level, various
pictograms such as the credit wedge, and pointers which point to pictograms on the membrane.
3.2 LCD Layout (what the icons mean)
The LCD is designed to give a clear and unambiguous visual indication of important meter functions
by means of language-independent pictograms:
Figure 2: Display Icons
3.2.1 Legend
1) Happy Face
2) Sad Face
3) Latching relay “OPEN” Indication
4) Latching relay “CLOSED” Indication
5) Information Mode Indicator
6) Power Indicator (W)
7) Power Indicator (kWh)
8) Icon Pointers
9) Remaining Credit Indicator (Credit Wedge)
10)Alarm Indicator
11)Numerical Display

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© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
3.3 Typical Operational Displays
3.4 Happy and Sad Faces
These two icons are used in combination to give a quick visual indication of good and bad status. For example,
if the meter were operating normally, the happy face would be on. However, if it were to be tampered, the sad
face would come on. Similar responses would apply during token entry e.g. entering an invalid credit token
would result in the sad face flashing for a short period of time.
Note that an out of credit condition is not considered to be a 'bad‟ status
and the happy face will be on.
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3.5 Latching Relay Status Indicators
Two icons are used to indicate the status of the internal latching relay.
Under normal operating conditions i.e. with the meter in credit, the latch will be „closed‟ and power is supplied to
the consumer. A second „open‟ indicator is used to indicate that the latch is open, e.g. when credit expires.
Under normal operating conditions e.g. with the meter in credit, the latch
will be closed. It will open when credit expires.
3.6 Information Mode Indicator
This icon turns on in response to pressing the i-key on the keypad. It indicates that the meter is in information
mode and the contents of various registers can be viewed.
Note that the information mode automatically times out after a period of 1
minute in the absence of any further interrogation.
3.7 Power Indicator (kWh)
This function is used whenever the displayed units represent power (kWh). It applies to both normal meter
operation, and when viewing registers via the information mode.
The icon will be ON when the latch is closed and the load exceeds the minimum creep load (typically 40mA)
and the icon will be flashing when the latch is open and there is no load in excess of the creep limit.
The power (kWh) icon will flash on and off if no measurable energy is being
consumed.
3.8 Power (W) Indicator
This function is used whenever the displayed units represent power (W), such as instantaneous power, or
power limit setting. It applies to both normal meter operations, as well as when viewing registers via the
information mode.
3.9 Remaining Credit Indicator
This „wedge‟ provides a quick visual indication of the remaining credit in the meter.
The actual credit levels at which the individual bars in the „wedge‟ icon
toggle are personalised at the time of manufacture but can be changed at
any time with a maintenance token.
The indicator functions as follows:
All four credit wedge icons are displayed if the value in the current credit register is above the
pre-set high credit level.
The three smallest wedge icons are displayed if the value in the current credit register is
somewhere between the pre-set low credit level and high credit level.
The two smallest wedge icons are displayed if the value in the current credit register is
somewhere between the pre-set low credit level and half of that level.
The smallest wedge icon is displayed if the value in the current credit register is somewhere
between zero and half of the pre-set low credit level.
All the credit wedge icons will be off when the meter runs out of credit (zero or negative
values).

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© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
When the remaining credit level reaches zero, the numeric display indicates
0.0 kWh. If, for any reason, the credit level is decremented below zero i.e.
negative, the display indicates 0. kWh. (no zero after the decimal point)
This is the case if the meter has been personalised not to display negative credit
Although there is no negative value displayed, it gives a quick visual indication that a negative value is present
(it is a requirement of some utilities to not show a negative credit value to consumers because in all likelihood it
indicates tampering with the meter).
3.10 Alarm Indicator
This is a „low credit‟ warning indicator that turns on if the current credit register value is greater than zero, but
less than half the low credit level. Under these conditions it is displayed in conjunction with the smallest credit
wedge icon.

Meter Operation Review 11/27
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4 Meter Operation
4.1 General
In this section the features and functionality of the prepayment meter are described in detail.
4.2 LCD Indications during Normal Operation
During typical operation, the LCD provides the following displays:
Figure 3: LCD Icons during the normal meter operation
Displays the current credit register value to a resolution of 0.1 kWh.
Displays any combination of the credit wedge icons (0 to 4 segments depending on the actual
current credit level in the meter.
Displays the happy face icon, irrespective of the credit register value.
Displays the latching relay status icon in either the closed or open position, depending on
whether the meter is in or out of credit.
Flashes the „kWh‟ icon if the meter is Creep mode (no power or very little power is consumed).
4.3 Entering Prepayment Tokens via the Keypad
Prepayment tokens are entered into the meter by keying in the numbers printed on the credit token via the
keypad. The numbers entered are displayed on the LCD as they are being entered and scroll from right to left,
with a space displayed at every fourth digit for ease of viewing.
Visual feedback is provided by flashing the happy face icon with each key press.
Audible feedback is provided by a „beep‟ on each key press.
Incorrect entries can be corrected with the backspace key (left arrow key),
which removes the rightmost digit on the LCD with each press. Two
backspace key presses in quick succession will clear the entire entry.
Acceptance of a valid prepayment token is automatic. Once a complete token has been entered, the meter
processes it and, depending on the result, displays one of the sequences described in paragraph 4.3.1.
Depending on what sequence is invoked, the keypad could remain locked for a variable period of time i.e. it will
not respond in any way to further key presses.
An incomplete token entry will be timed-out after 30 seconds, after which the LCD reverts to normal operation.

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© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
4.3.1 Happy & Sad face indications
Figure 4: Typical Happy & Sad face combinations
4.4 Token Processing
Depending on the type of token entered into the meter, it will result in one of the display sequences
described above.
4.4.1 Incomplete Token
A token entry is timed out if no key is pressed for more than 30 seconds. On time-out:
The token number is cleared off the display.

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4.4.2 Complete Token
If a complete token is entered, the meter:
Locks the keypad.
Proceeds to process the token number.
Once the token has been processed, the meter displays the remaining credit.
4.4.3 Token Accepted
The running ladder pattern on the credit wedge is displayed.
4.4.4 Token Accepted as a Valid Key Change Number
Two 20 digit tokens are required for a key change.
The scrolling credit wedge is displayed.
The key revision and key type, followed by the tariff index, is displayed during the above scrolling sequence.
4.4.5 Incorrect Token
If the token is rejected, the following will be displayed:
The happy face icon is turned off.
The sad face icon is flashed for the reject time.
4.4.6 Duplicate Token
If the token is rejected because it has previously been entered i.e. a duplicate token:
Both the happy face and sad face icons are flashed simultaneously for 5
seconds.
4.4.7 Expired Token
If the token is rejected because it is older than the oldest token in the meter log i.e. „expired‟:
Both the happy face and sad face icons are alternately flashed for a period of 5 seconds.
4.4.8 Token Overflow Rejection
This occurs if the token is valid, but rejected because the current credit register would overflow. The following is
displayed:
The happy face icon is flashed.
The sad face icon is turned on for 10 seconds.
The token can be re-used at a later stage.

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4.5 Token Decryption and Processing
The meter accepts information transferred as specified in the Standard Transfer Specification
STS tokens comprise of 20-digit numbers.
The following STS token types will be recognised and accepted:
Electricity credit (meter-specific token)
Set 1st dispenser key (meter-specific token)
Set 2nd dispenser key (meter-specific token)
Clear tamper (meter-specific token)
Set maximum power load or power limit level (meter-specific token)
Set current credit levels (meter-specific, proprietary token)
Clear credit (meter-specific token)
Initiate dispenser test (non meter-specific token)
Commissioning token (non meter-specific, proprietary token)
Commissioning token (meter-specific, proprietary token)
Decommissioning token (meter-specific, proprietary token).
Set Options Register (meter-specific, proprietary token).
4.5.1 Electricity Credit Token
The electricity credit token transfers a variable quantity of credit to the meter.
4.5.2 Set 1st Dispenser Key Token
Key changes are occasionally carried out to maintain the security of a pre-payment system. Unless the
prepayment vending system and meter are both operating on the same key, tokens vended from that system
will not be accepted by the meter.
To effect a key change, two tokens (set 1st dispenser key and set 2nd dispenser key) need to be issued and
entered into the meter within a 5-minute period of each other.
Set 1st dispenser key and set 2nd dispenser key tokens may be entered in
any sequence i.e. the 2nd dispenser key token may be entered first.
Note: Various ancillary functions e.g. clearing the meter log may be embedded into the key-change process
(refer to the STS specification).
4.5.3 Set 2nd Dispenser Key Token
Refer to paragraph 4.5.2 above.
4.5.4 Clear Tamper Token
If a meter has been tampered, normal operation can only be restored by entering a tamper reset token.
A tamper reset token also reset the power-fail counter.
4.5.5 Set Power Limit Token
This token sets the power limit level for the meter.
4.5.6 Set Credit Alarm Levels Token (Proprietary Token)
On accepting a credit alarm level number, the meter sets the appropriate high and low credit levels. These are
the levels at which the segments in the „wedge‟ of the LCD credit indicator toggle
Note: If any of the credit levels transferred via the token is zero, the token is accepted, but the respective credit
level is not updated.

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The set credit levels token is not defined in the STS specification. It is a
Cashpower specific feature, and it uses one of the proprietary dispenser
specific management token subclasses.
4.5.7 Clear Credit Token
On accepting a clear credit token, the meter clears any remaining credit to zero and opens the latching relay,
thus interrupting the electricity supply to the customer.
4.5.8 Initiate Dispenser Test Token (Meter Non-Specific Token)
There are a number of non meter-specific tokens that can be used to test various functions on the meter.
On accepting an initiate dispenser test token, the meter executes all the tests that are embedded in that
particular token. The following tests are supported:
Function
Token Number
Open the latching relay
0000 0000 0001 5099 7584
HMI test - turns on all the LED‟s, displays all
segments on the LCD, and activates the buzzer
0000 0000 0001 6777 4880
Display the total units counter
0000 0000 0002 0132 8896
Display the key revision number and key type
1844 6744 0738 4377 2416
Display the tariff index
3689 3488 1475 5332 2496
Display the power limit level
0000 0000 0012 0797 4400
Display the tamper state
0000 0000 0022 8172 8512
Display the instantaneous power
0000 0000 0044 2920 8064
Display the software version number
0000 0000 0087 2419 5840
Test all the above functions (tests run
sequentially)
5649 3153 7254 5031 3471
In a test sequence (test all), each test has a duration of 2.5 seconds, and is performed in the above order. For a
single test per token, the test duration is 5 seconds.
On completion of the test sequence, the meter returns to its normal mode of operation.
4.5.9 Commissioning Token (Non Meter-Specific, Proprietary Token)
This is a proprietary STS token i.e. it can only be used on a Landis+Gyr
STS meter: 1268 2136 5508 1001 3746. This is a non meter specific
number.
It is typically used to assist meter installation personnel by ensuring that the load remains disconnected and the
tamper detect sensing switch function disabled (meter decommissioned).
Once the installation is complete and the number entered:
The latching relay closes
The tamper detect sensing switch function is enabled.
4.5.10 Commissioning Token (Meter-Specific, Proprietary Token)
This is a meter-specific token but in all other aspects its operation is the same as described in the paragraph
above.
Note: An already commissioned meter rejects a commissioning token.
4.5.11 Decommissioning Token (Meter-Specific, Proprietary Token)
On accepting a decommissioning token, the meter opens the latching relay (load disconnected) and disables
the tamper detect sensing switch function.
Note: An already decommissioned meter rejects a commissioning token.

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4.5.12 Set Options Register (Meter-Specific, Proprietary Token)
On accepting this token, the “Changeable Options Register 0” is set according to the 8-bit value in the token.
Care must be taken when using this feature, as the operator would not
know the settings in the meter, and various parameters could be set/reset.
The parameters are as follows:
Enable/Disable Tamper Function
Tamper / Do Not Tamper on Significant Reverse Energy
Disconnect / Do Not Disconnect on Power-Fail
Non Automatic / Automatic Latch Reconnect
Refer to paragraph 5.1.15 for more detail.
4.5.13 Commissioning and Decommissioning the Meter
The function of being able to set the meter into the decommissioned / commissioned mode offers several
advantages to meter installation personnel. If power is applied to the meter during installation and the meter
terminal cover not yet in place, the meter will detect this and enter into the tampered mode, thereby
disconnecting the supply to the customer. A meter-specific tamper reset token then needs to be generated at
the vending system to rectify the situation.
When setting the meter into the decommissioned mode, the following occurs:
The tamper detect sensing switch function is disabled.
The latching relay is set into the open state.
When setting the meter into the commissioned mode, the following occurs:
The tamper detect sensing switch function may be either enabled or disabled.
The latching relay operates as normal.
The meter‟s commissioned / decommissioned status can be observed in
the meter state register - refer to paragraph 5.1.13 for more information.
4.6 Power Limiting
The power-limiting feature allows utilities to set the maximum load that can be drawn by customers. The setting
can be changed when necessary via a set power limit token from the prepayment vending system.
This algorithm is included in the meter‟s software and is implemented as follows:
If the preset power limit threshold is exceeded, the latching relay will open for a period of 30
seconds (power limit trip period), after which it will re-close (either automatically or manually -
refer to paragraph 4.7).
If the power limit threshold continues to be exceeded, the above process is repeated.
If, after 4 power-limit events within a 15-minute window, the limit is still being exceeded
because of excessive energy consumption, the latching relay will be opened for a period of 30
minutes (the power limit lockout period).
At the end of the lockout period, the latching relay will re-close (either automatically or via a
manual operation on the keypad) and, unless the excessive loading has been removed, the
process will be repeated. Note that tokens may be entered and the information modes
accessed as normal during the power limit lockout period.
If the power drawn by the customer is reduced in response to a power limit disconnect, the
event will be ignored after 15 minutes has elapsed.

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The LCD will display the following during the two conditions:
Figure 5: LCD Showing "Power Limit Trip" - Disconnection for a 30 second period
Figure 6: LCD Showing "Power Limit Lockout" - Disconnection for a 30 minute period
Power Limit is not a form of safety overload protection. It is designed to
generally limit the overall usage of power in a particular area (possibly
dictated by reticulation limitations or linked to a tariff allocation).
4.7 Automatic/Manual Load Reconnection
In some instances, local safety regulations require that the meter not automatically re-close the latching relay
after, for example, a power limit trip. Under these conditions, the latching relay will remain in the open state until
such time as a key is pressed on the keypad.
Using the example of a power limit trip, the latching relay will open and remain open for a period of 30 seconds.
At the end of this 30-second period, the display will return to normal but, instead of the latching relay closing, the
latching relay status icon on the LCD will start to flash, toggling between an open and closed state. This is a
visual indication that the latching relay may now be manually closed, by pressing any key on the keypad.
When the latching relay open & closed status icons on the LCD start to
flash alternately, this is a visual indication that the latching relay may be
manually closed by pressing any key on the keypad.
In the event of the latching relay opening due to expiry of credit, it will only be able to close again on entry of a
valid credit token.
The manual action of entering a credit tokenvia the keypad, results in the latching relay closing when the last
digit of the token is entered and accepted by the meter.
Automatic/manual load reconnection is a configurable option, set at the time of manufacture. It may also be
changed at any stage with a suitable engineering token.
4.8 Disconnect on Power Failure
This option, configurable at the time of manufacture, forces the meter‟s latching relay to open whenever there is
a power failure. The option can be invoked as a means of preventing the meter from being installed fraudulently
with line and load connections reversed, in which case the meter will never power up once the latching relay is
open.

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4.9 Anti-tamper Features
4.9.1 General
The meter is mechanically sealed against tampering through the use of a factory sealed screw plug on the rear
panels and a utility-sealed wire seal on the front of the meter.
The use of these mechanical seals ensures that there are visible signs of tampering if unauthorised entry to the
system is attempted.
4.9.2 Anti-Tamper Switch
This tamper facility automatically detects if the terminal cover of the meter is removed. This condition will set the
tamper condition thereby opening the latching relay. A meter specific tamper reset token will be required to reset
this condition.
The Tamper Detection function may be enabled or disabled during production, or by means of a Set Options
Register token –refer to paragraph 4.5.12
To check if the tamper facility is enabled or disabled refer to register 035,
refer to section 5.1.15.
The tamper condition may be monitored by using the information functions
To check if a meter is tampered, refer to register 031, (section 5.1.13), or
use the non meter specific token (0000 0000 0022 8172 8512) to display the
tamper state. A value of 1 displayed after the token has been accepted
means that the meter is tampered.
4.9.3 Reverse Energy Detection
The meter includes a Significant Reverse Energy (SRE) detection feature. If the line and load wires are
swapped during installation, the meter will continue to operate and decrement credit, however, the meter can be
factory-programmed to tamper and disconnect the load should SRE be detected.
The reverse energy condition may be monitored by using the information functions –refer to section 5.1.13 and
5.1.15
4.9.4 Magnetic Tamper Detection
The meter incorporates a magnetic tamper detector. When the meter senses a magnetic field strength above a
pre-programmed threshold level, it disconnects the supply to the consumer.
As with the power limit trip condition, the magnetic tamper condition opens the internal latching relay for 30
seconds. Should magnetic interference be detected more than 5 times in a 15 minute window, the latching relay
will open for 30 minutes.
The Magnetic Tamper state may be monitored by viewing the register 037,
(press information button & then 037) refer to paragraph 5.1.17.
4.9.5 Resetting a Tamper Condition
Before resetting a tamper condition, care must be taken to remove the cause of the condition, e.g. ensure that
the tamper switch is closed. Failing to do this will cause an immediate tamper condition.
If a meter has been tampered, normal operation can only be restored by entering a clear tamper token.

Meter Operation Review 19/27
Cashpower Gem Lite –User Guide © Landis+Gyr (Pty) Ltd
4.10 Virtual Token Carrier (VTC) Interface
This port is available via a removable plug at the rear of the meter and should only be accessed when the meter
is disconnected from power. It allows for meter data such as remaining credit to be extracted in the event of an
electronics failure.
From a safety point of view, the meter must not be powered when
accessing this port the field tool provides the necessary low-voltage supply
to power the logic circuitry.

20/27 Review Information Functions
© Landis+Gyr (Pty) Ltd Cashpower Gem Lite –User Guide
5 Information Functions
Pressing the information key, invokes the meter‟s information mode (the information icon on the LCD
turns on and all display rows, refer to Figure 7 below). The contents of various registers can now be
viewed by entering the appropriate, 3-digit register code.
Figure 7: LCD showing the display in the information mode
Once in information mode, toggling between different registers may be
done on an ongoing basis by entering the appropriate 3-digit code i.e. the
information key does not have to be pressed again.
To exit the Information mode, press the information key or, in the absence of any other key presses, it
will automatically return to the normal display after a period of 1 minute.
5.1 Information Register Functions
Information Register Functions
Info Register
Number
Function / Meter Parameter
000
11-Digit Electricity Dispenser Number
001
Instantaneous Power
002
Current Credit Register
003
Total Units Counter
005
Accumulated Credit Register
008
Current 30-day Consumption
009
Previous 30-day Consumption
012
Low Credit Level
013
High Credit Level
014
Power Limit Level
030
Meter State Register –Upper
031
Meter State Register –Lower
032
(Fixed) Option Register –Upper (Not used)
033
(Fixed) Option Register –Lower