Multi-drop bus to RS-232 or USB PC interface ( MDB-RS232 ) | | The vending machine standard NAMA Multi-Drop Bus (MDB) may now
beinterfaced to a PC using the MDB-RS232. The MDB-RS232 allows Coin
Acceptance, ChangeDispensing, smart card reader, magnetic swipe,
credit card reader,bill acceptor and billvalidation all controlled
by the PC.Conforms to all NAMA MDB specification and is compatible
with any MDBcompliant vending device. Hardware interface comes with
cables,user'sguide and user's protocal. |
( For Pulse type Coin validator and bill acceptor to PC, please
check: PULSE-PC adapter ) This Interface Unit (IU) is designed to convert the MDB Bill
Acceptor (BA) and MDB Coin Changer (CC) protocol to RS-232 serial
protocol. The IU functions as a slave to a master control system.
The master may be any control system that supports RS-232 serial
communication, for example a PC. DESCRIPTION：
This Interface Unit (IU) is designed to convert the MDB Bill
Acceptor (BA) and MDB Coin Changer (CC) protocol to RS-232 serial
protocol. The IU functions as a slave to a master control system.
The master may be any control system that supports RS-232 serial
communication, for example a PC. OPERATION:
The master and slave communication is based on master requests and
slave replies. The master sends a status request (or command) to
the IU and IU answers by sending its current status. The IU’s
typical response to the Master’s request (polling) consists of a
header and data bytes. If there is no BA or CC activity, the status
is one byte, the header only. When the IU receives data from the BA
or CC, it sends a header followed by data bytes in the response to
master’s status request. The master must always poll (query) the
IU. If the IU does not receive a query from the master in the
predefined time slot or IU does not recognize master messages 10
times in row, it will inhibit the BA and CC acceptance. At power
up, acceptance of the BA and CC is inhibited. SPECIFICATION:
Communication format
Baud rate | Start bit | Data bits | Parity | Stop bit | 9600 BPS | 1 | 8 | NO | 1 |
Timing Specification:
Inter-byte (max) | Response (max) | Master pollingtimes every | Time IU waitsfor the Master’s poll before inhibiting acceptance of
the BA and CC (max) | 1 ms | 50 ms | 150 300 ms | 3 second |
Hardware Specification.
Power | Cable | Dimensions | Weight | Min 20 VDC
Nominal 24...34VDC (or 24...30VAC)
Max 39 VDC
Consumes an idlecurrent < 0.05A
0.5A for 1 sec.when accepting bills | Standardcomputer serial cable Standard MDB cable | approx. 100 x 50x 30 mm | approx. 115 g |
Nomral Package List: MDB-RS232 Adapter Board (1pcs) | MDB Cable From MDB-RS232 to Bill acceptor and Coin validator (1pcs) | RS232 Cable From MDB-RS232 to PC (1pcs) |
Optional Parts: Power Supply For MDB RS232 adapter board ( 24VDC 3A) ReferencesMDB ProtocalThe MDB Spy program is implemented according to the MDB
specifications asstated in : NAMA MDB / ICP protocol specification Supported by the NAMA, EVA and EVMMAorganizations. Version 1.0 October 14, 1998 This protocol can be obtained from the NAMA organization | 
