NV10 Operations Manual – GA333-3
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© Copyright Innovative Technology Limited 2005
7.6: MDB – Multi-Drop Bus / Internal Communications Protocol (IF5)
To use the MDB mode an IF5 interface box must be fitted to the NV10 Validator and DIPswitches 3 &
4 must both be set up, with the MDB option of the interface firmware loaded into the NV10.
MDB defines a serial bus interface used in electrically controlled vending machines (see figure 7).
This is a 9600 Baud Master-Slave system where the NV10 MDB banknote validator is a slave to a
master controller. A master has the capability of communicating with 32 peripherals or slaves. The
master is defined as the Vending Machine Controller (VMC).
Figure 7- MDB Opto Isolated Input / Output circuits
The NV10 MDB banknote Validator is assigned a unique address – 00110XXX binary (30H). The
VMC polls the bus to detect presence of the NV10 MDB Validators or to get information on current
status of the Validators.
The Validators respond when asked for activity with an acknowledgment, negative acknowledgment
or a specific reply, depending on its current status. Bus crashes are avoided as the Validators
respond to being polled only by the VMC.
The international country code must be set for the country in which the Validators will be operating.
This is the international telephone code for that country. The code is represented as two bytes
For the USA the country code is 00 01
For Great Britain the code is 00 44
The scaling factor must also be specified for each Validator. All accepted note values must be evenly
divisible by this number.
•
This number would be set to 100 (Hex 64) for the Euro or Great Britain.
•
The number would be set to 1000 (Hex 03E8) for Romania.
•
The number of decimal places must also be programmed for each Validators
•
The number would be set to 2 for Euro or USA
•
The number would be set to 3 for Romania
NV10 MDB Slave
Ground Signal
Receive
Transmit
Note:
§
Please refer to the Multi-Drop Bus specification for the suggested current drive circuits
available.
§
The NV10 supports the MDB protocol version 1, level 1
§
For detailed information and full protocol specification please refer to NAMA
