A user interface unit User Interface Unit UIU(UIU) is a remote access terminal for STS prepayment
The Standard Transfer Specification STSmeters. The device is placed inside the user's premises, while the energy meter is mounted outside and mostly not direct accessible. Some meter manufacturers are using the term customer interface unit (CIU). The functions are the same.
The main purpose is to charge the meter with credit. By various short-codes, it's possible to do many kinds of queries for meter status and consumption. The short codes are not unified, so refer to your user manual for operation.
UIUs are paired with the energy meter when leaving our factory. Depending on the utility order, CLOU interface units are communicating with the meter by radio frequency (RF), power line (PLC) or by wired RS-485.

If the UIU is not communicating with the energy meter, you can pair it again by typing 1593570 and the 11 or 13 digit meter number, then press the enter key (red or blue). The meter number is printed on the meter and on your customer card, which you use to buy credit.
After successful pairing, the display will show OK.
Note: This is only working for CLOU energy meters.Discover the Power of Electronic Energy Meters with Our Expertise
There can also be other reasons for a communication fail. If the UIU is connected by power line and you are disconnected, batteries need to be inserted in the UIU to recharge the meter or query the status. If this meter is in tamper mode, a recharge is impossible before clearing the tamper.How to get a Clear Tamper Token?
Editor's note: This article was originally published in August 2020 and has been updated for comprehensiveness.
My ciu is showing error whenever I press enter requesting for anything what could be the problem?
Please ensure first you have input the correct format of short codes or token.
I lost my prepaid meter remote but I have another one. The are of different brand though. So pls how can I program it to start working with my meter
Since there is no standard communication protocol, the remotes (UIU/CIU) work only with the related brands.
Why is My UIU showing error 06 when I enter my meter number, how do I resolve these
You need to enter a 20-digit token given by your power company. Your meter number has only 11 digits. That's why you see error 06.
Can I convert my phone to uiu because my Is bad
No, you can't.
can i use your CIU with any other STS meters models ?
There is no standard communication protocol for CIU/UIU, so it's not possible to communicate with other STS meter models.
Why is my balance not changing for the past 5days after recharging my user's interface
The user interface unit (UIU) transmits only the token to the meter. The meter will be charged immediately after transmission.
After entering the token, the UIU shows an information, e.g. Accept or Reject. See the full explanation here.
How does one know when the meter is on tamper mode
The first indication is, that you have no power at your home. If the meter display is also off, there is a general outage in your area. If the display is on, and you see a raised hand symbol (CLOU meters), the meter is in tamper mode. The power company can additionally read out the tamper-log to see what happened and when.
Can a CIU be used to communicate with a mobile device?
Can a CIU be used to pass a query "does the meter have power?"
Thank you for your question. Customer Interface Units (CIU/UIU) are only designed for short distance communication. If your meter has a connection to a central utility system (Advanced Metering Infrastructure AMI), your utility might pass such queries to your mobile device via a website. You need to ask your energy provider. In many countries, this technology is just coming up.
Can a single phase uiu be used to a 3phase meter? Or is there any difference between single phase uiu and 3phase uiu?
The firmware is different. A three-phase meter has more parameters. Use only the UIU, delivered with your meter.
I want to pair a newly purchased CloU meter but the owner misplaced the meter number,, How can I recover his meter number please
The meter number has 11 digits and is printed on the meter front plate. For CLOU meters, it starts with 54.