Error Codes of STS Prepayment Meters

STS (Standard Transfer Specification) prepayment meters take digital medium as information exchange media. Users load in pre-purchased credit and then the meters take credit as their billing to realize the functions of active energy measuring and prepayment control and realize remote communication and remote control via module.
Local power companies or utilities use prepayment meters to avoid debts by charging power bills in advance. Additionally, prepayment smart meters with automatic reading function reduces cost of manual collecting meter data.
For end-customers, they can check their meter load in real time to use power reasonably. They can also recharge meters in any place and any time, instead of going to local power company to pay for.

CLOU STS Prepayment Meters

We have many STS prepayment meters, such as CL730S22 and CL710K22. You can also find more information about prepayment meters here.

Single Phase Meter CL710K22
Single Phase Meter CL710K22
Three Phase Meter CL730S22
Three Phase Meter CL730S22

Differences between TOKEN and Meter Numbers

TOKEN numbers and meter numbers are two totally different things.
According to the STS standard, a TOKEN has only complete 20 digits.
While CLOU STS meters have 11 digits. Other CLOU meters also have 12 digits.
The length of meter numbers is customized.
When you input a Token by which the prepayment meter can not work, the meter will show error codes. Specific reasons are cited one by one as below. If your meter equips an UIU (User Interface Unit), error codes also shows on its LCD.

Error Codes Shown on CLOU Prepayment Meter

CLOU regulates prepayment meter error codes in a certain statement according to the IEC62055-41 chapter 7.1. Almost all CLOU prepayment meters have the same error codes.
Here takes error codes shown on the CL730S22 three-phase meter as an example.

Meter Display Information

  • OPEN Any meter cover was opened
  • DISTU Magnetic disturbance detected
  • OVER PO Power exceeds the limit
  • VOL-OVER Voltage is over allowed threshold
  • CUR-OVER Current is over allowed threshold
  • CUR-UNB Current unbanlance occured
  • N-DST Neutral line is disturbed
  • CT-BYPAS Meter is bypassed
  • CT-OPEN Meter current circuit is open
  • VOL-UNB Voltage is unbalanced
  • HIGH-TMP Temperature too high
  • LOW-PF Power factor too low

UIU Display Information

  • ACCEPT TOKEN accepted
  • REJECT TOKEN rejected. The 20-digit TOKEN input is not generated from the designated platform.
  • OLD TOKEN expired
  • USED TOKEN used
  • FULL Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted.
  • OK Operation accepted
  • Err_01 Error in manufacturer code. The Manufacturer Code value in the Class 1 token does not match the Manufacturer Code value for the Decoder.
  • Err_02 Key expired error. The TID (Token Identifier) value as record in the token is larger than the KEN (Key Expiry Number)stored in the payment meter memory.
    Solution: First, please check your meter KEN value if it has expansion space or not; If the number is already maximum, shift the TID and change the Base Date in the energy selling system into “2014” option.
  • Err_03 DDTK (Decoder Default Transfer Key) error. The Decoder has a DDTK value in the DKR (Decoder Key Register): a Transfer Credit token may not be processed by the Meter Application Process in accordance with the values given in credit.
  • Err_04 Overflow error. The credit register in the payment meter would overflow if the token were to be accepted; the token is not accepted. (Some meter types are showing Err_04 instead of FULL).
  • Err_05 Key type error. The key may not be changed to this type in accordance with the key change rules.
  • Err_06 TOKEN format error. One or more data elements in the token does not comply with the required format for that element. That's say, to aviod this error, 20 digits of the TOKEN are correct and complete, and the TOKEN must be valid and unused. For example, the error shows when one only inputs 19 digits.
  • Err_07 TOKEN range error. One or more data elements in the token have a value that is outside the defined range of values defined in the application for that elements.
  • Err_08 TOKEN Function error. The particular function to execute the token is not available.
  • NULL Reserved

Troubleshooting to Pairing A UIU with A Meter

If something wrong happens while paring a UIU (User Interface Unit) with an energy meter, the following steps can be taken to initiate the UIU for troubleshooting.

  • Step1: Input "1593570" + "999" + "Enter" to initialize the UIU.
  • Step2: Input "1593570" + "11-digit meter number" + "Enter" to pair the meter with UIU.
  • Step3: Input "999" + "enter" to check the paired meter, and "12-digit address" will be displayed on the UIU.


So far, we have received a great number of comments about meter error codes and TOKEN. This article aims to at least provide a fundamental explanation to error codes.
For visitors who are finding information about them, wish this article can help you.
If you have more questions about error codes, just leave a comment below to discuss it.
Thank you for your reading and best wishes.

Editor's note: This article was originally published in November 2021 and has been updated for comprehensiveness.

88 Replies to “Error Codes of STS Prepayment Meters”
    1. For CLOU meters, error 04 means register overflow. The token can't be accepted unless your register has space enough to store the units without rolling over. E.g. you have 999995 units, and you want to top up 5 units, the register would show without this security measure zero units. Since this is only a theoretical possibility, because no one is buying this quantity of credit, I assume that the meter is from another manufacturer.

  1. My meter remain with open relay even if I put my clear temper and we confirm the clear token was right
    We are try to check voltage is 208

    1. If the raised hand is still shown in the display, the reason for the tamper is still not resolved. If only the relay symbol is shown, there can be other disturbances in the grid, like under-voltage. This problem restores automatically, once the situation comes back to normal.

  2. Hello sir,
    I am from Bangladesh.
    I want to know —
    How can off CLOU 440 V Energy miter Relay for 3/5 minutes?
    Please you give me a code.

    1. I haven't got the point, but there is no code for temporary disconnection.

  3. Good evening from Nigeria.
    Please what is the meaning of C-OPEN.
    What is the cause and how can I clear the code.

    Thanks in anticipation

    1. C-OPEN is no error message for CLOU meters. I guess it indicates a cover open tamper. The tamper can only be cleared with a special token (clear tamper token) issued by your power company.

    1. There is no code for this purpose. To completely switch off the power supply in your home, it's best to utilize the main circuit breaker. This safety measure ensures that all electrical circuits and appliances are fully powered down.

  4. Thanks for the updates.
    I'm a electronics technician, kindly help me with a book that deals with Cloug meter repair.

    1. If an electronic energy meter has a malfunction, it can only be repaired by the manufacturer. The repair includes in any case a re-adjustment and a re-calibration. This makes the cost of repair in most cases higher than the cost of replacement.

    1. Reject occurs when the token input is wrong, or the token was issued for another meter number. See more information here.

    1. It's a DLMS OBIS Code. The code c.51.0 represents the cumulative active energy imported register, which is the total amount of energy consumed by a customer from the utility grid over a period of time, usually in kWh.
      Some meter manufacturers use this code to show the balance credit, means the amount of credit remaining on a customer's prepaid electricity account.
      For CLOU meters, the indication is 07.

  5. The meter LCD is indicating a black openpaddlock on it and it doesn't close when you put in a token generated to close the relay, although the terminal cover is covered well…

    1. Electronic energy meters have several elements for tamper detection. The terminal cover is only one of them.
      Your power company can read the meter tamper log to see which tamper has caused the disconnection and whether it's restored.

  6. I have lost the meter card and my kid destroyed the front badge where the token number is indicated, please help

    1. For CLOU meters, the meter number is lasered and hard to destroy, especially for children. Your power company has to take care that the meter is installed, inaccessible for children. You have a contract with your power company, which is also indicating your meter number. In worst case, let them check your meter number in their database.

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