3 Other operating modes of the G-18.mft - NRI

G-18.mft with vending machine control system OTHER OPERATING MODES OF THE G-18.MFT
Serial operation
For vending machines with a serial interface, the coin validator G-18.mft can
be used in two different operating modes, i.e., as a slave or as a master.
Slave coin validator operation
Master operation
In slave operation, the G-18.mft is used as an exclusive coin validator. The
coins inserted into a vending machine are checked for their properties and
are accepted for sale or rejected and directed into the return area as a result
of this inspection.
The communication of the coin validator with the vending machine control
system is carried out via the MDB protocol or the S1 protocol. Accordingly,
the vending machine functions as a master and the coin validator as a slave.
The MDB protocol (MDB = Multi Drop Bus) is used in the case of the
G-18.mft with BDTA (BDTA = Bundesverband Deutscher Tabakwaren-
Großhändler und Automatenaufsteller) (federal association of German
tobacco wholesalers and vending machine installers) restrictions for:
• voltage supply and
• battery operation.
The S1 protocol is an MDB protocol specified for NRI coin validators with
individual restrictions and commands for:
• voltage supply and
• sorting.
You can obtain further information about the MDB interface and S1 interface
in the
• BDTA MDB specification, which is available to you at the BDTA
• NRI S1 specification for the G-40 S1, which NRI will gladly place at
your disposal upon your request.
The G-18.mft is used as a master whenever it is supposed to control
devices via the MDB protocol in addition to the coin inspection (see above).
The communication of the coin validator with a card reader, display or other
external device is carried out via the standard MDB protocol (MDB = Multi
Drop Bus), with the coin validator functioning as a master and all connected
devices, such as a card reader or display, functioning as a slave.
You will find detailed information about the MDB interface in the "NAMA
document MDB/ICP, 2.0" (www.vending.org).
National Rejectors, Inc. GmbH, Buxtehude
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