Student Apartments

prepaid smartmetering

iSAtech Prepaid Management System Overview Installation Dormitory


The user can check his current balance at any time via the Internet or smartphone and top it up via online payment systems such as PayPal. The consumption of the last days and weeks can also be checked.

The dispensing units are installed together with the meters in the apartments and networked by radio or cable. They communicate with the iSAtech Cloud Server via the Internet is realized with a gateway. Credit information is loaded from the server and charged according to consumption.

The dispensing units are installed in the apartments and networked by radio or cable. They communicate with the server via the Internet using a simple router. Credit information is loaded from the server and charged according to consumption.

The comfortable software offers a quick overview of all information and all transactions. There is no need for consuming readouts or billing of service charges.

The dispensing unit

The dispensing unit can be installed in the sub-distributor of the flats on a HUT rail. The dispensing unit is used for the controlled dispensing of electricity, water, heat and device operating times. For this purpose, either the water meter and valve or the electricity meter and contactor are connected to the dispensing unit. Communication with the router can take place via 2.4 GHz, 868 MHz radio, LoRa or via RS484+ cable. Alternatively, M-Bus or wireless M-Bus meters can be used.

The dispensing unit receives the budgets and credits information, tariffs, configuration, and control data from the server and processes all data locally. This enables accurate billing and dispensing, even if the Internet connection is interrupted or not continuous.

According to the credit/budget and tariff, the valve or contactor opens and closes. The consumption data is regularly transferred to the server, and the credit can be viewed and recharged via smartphone. In case of budget overruns, warnings can be sent via e-mail, SMS, or Messenger. For example, in common rooms, washing machines and dryers can be controlled with the dispensing unit. This makes it possible that the use of the devices is also billed via the student's credit balance. The washing machine is conveniently booked and billed via smartphone.

The credit management

The user can be provided with a monthly or annual budget that is billed as part of the rent or can load and manage his credit balance independently via a web portal on the Internet.

The purchase of credits can be made conveniently by bank transfer or PayPal, for example. The operator of the system sees all transactions in the management software. Furthermore, all customer data, credit sales, number of users, and other statistical data can be created and viewed over any period of time.

Mobile top-up of credit

The credit can be purchased by the user independently via the Internet or using a smartphone. Thanks to the system's flexible and powerful interfaces (APIs), payment can be made via any online payment provider, such as PayPal. It is also possible to integrate bank accounts via HBCI and manually top up through the administrative staff.

The request and release of credits are made via secured and encrypted connections to the iSAtech Server Cloud. The server establishes communication with the dispensing units and all consumption, payment and user information can be conveniently managed via the iSAtech PayU-Manager GUI. The paid credit is automatically credited to the user's dispensing unit. Water, electricity, heating, washing machines, dryers etc. can be used until the credit is consumed. A timely warning informs the user when their credit is low. Credit lines can be set up to avoid interruption of supply at weekends.

Installation examples

Prepaid dispensing systems

xample of installing the iSAtech control unit for electricity and water in the sub-distribution board in the apartment with contactor and electricity meter. Networking via RS485 cabling in the building.


Example of installing five gateways for 13 lines to connect the control units with the Prepaid Metering Cloud via the Internet. Supply with redundant, central energy feed.


  • Prepaid and budgeted dispensing of electricity, heat, water and equipment operating times
  • Budgeting with annual or monthly budget possible
  • App for the residents: overview of their own consumption, booking of washing machines and dryers as well as independent recharging of credit
  • Warning when the budget is exceeded
  • Online payment (e.g. PayPal, HBCI connection) or convenient top-up of credit balances by the administration
  • Connection of washing machines, dryers, showers
  • Usable with iSAtech Prepaid Controller, with M-Bus or wireless M-Bus meters
  • Connection of displays for the display of consumption data, credit and management messages (message system with read confirmation) possible
  • Integration into existing online system possible
  • User interface extensively customisable
  • Extensive reporting and evaluation functions
  • Free and flexible: software as a cloud solution or on-premise
  • Scales perfectly: Profitable already from one installation with one measuring point