RS-485/RS-232 Ethernet converter MBET-3

Ethernet converter MBET-3 for modbus RTU systems

MBET-3 is an internet/ LAN data transceiver for use in remote reading systems, mostly modbus RTU and m-bus. It has industrial switching power supply, RS-485/RS-232C interface for connection to RS-485 networks as a master converter and standard 10/100 Ethernet interface. That way modbus devices can be easily read through LAN or Internet with proper software. MBET-3 can be involved in networks with up to 250 modbus RTU or other RS-485 devices. It has built-in DHCP for ease of installation, but if needed DHCP can be turned off and user can set manually needed IP, mask and gateway IP addresses. MBET-3 allows up to six external operators (IP addresses) to connect (or be connected to) and read data. Moreover, for a given data operator only selected mediums are allowed for reading. Automatic readout can be set and performed among with other useful functions in remote reading systems. Communication protocol is Gineers development, over TCP/IP.

MBET-3 is specially designed for remote modbus RTU systems, but can be used in other applications as well. It comes in aluminium enclosure and is mounted on a standard DIN-rail, usually in industrial enclosures.

user manual

Technical characteristics of MBET-3

connection protocol TCP/IP
connection speed 10/100 MBit
power supply 150-250 VAC
power consumption < 1 W
serial port bps 1200/2400/4800/9600/19200/38400/115200 bps
work temperature from -20° C to +50° C
storage temperature from -50° C to +90° C
humidity 40 ÷ 90 %
dimensions (HxWxD), mm 105/107/74 mm
protection class IP30
display 3 LEDs (on, comm, Tx)
own weight 320 g

Operation of MBET-3

МBET-3 begins operation immediately after power-up. After initialization (about 2s), MBET-3 enters “Command mode” /checks for connection time/. MBET-3 can act as a client or as a server. If MBET-3 is set as a client, the connection with servers is initiated by the device, i.e. MBET-3 can be connected in local network without real static IP-address. All of the contacted servers must have static real IP-addresses in order for MBET-3 to be able to connect to them. MBET-3 can contact up to six servers – two “control” operators and four “data” operators. The two control servers can program all network access settings and have no access to the transmitted data. Likewise, the data operators can access only the data, but cannot program any network parameters. If it is needed for an operator to have access both to the network settings and the data, its IP-address must be set both as control and data operator. Accessible mediums for every data operator may be programmed, so, for example, the operator which monitors water consumption, cannot access the data, monitored by gas supplier and vice-versa. MBET-3 tries to connect to the servers after predetermined period of time (default 1h). Each of the servers can accept or reject the incoming connection. If the connection is accepted, MBET-3 starts with identification data packet to identify the remote reading network, connected to this particular MBET-3. After identifying the network server can reprogram network parameters (for control operators) or access network data (data operators). When all parameters are programmed or needed data is read, server must send TCP packet for closing the connection. After receiving this packet, MBET-3 closes the connection and tries to connect to the next server in the list until all the servers in the list are contacted. If no close connection packet is send or MBET-3 cannot connect to the server, it waits for predetermined period of time and closes the connection, if no data exchange occur. This process is repeated continuously, connection attempts are programmable period of time.

If MBET-3 is set as a server, it just waits for remote connections on specified port. After connection request arrives, MBET-3 checks its internal IP list and if remote IP and port number are valid - establishes connection. If no communication occurs for predefined period of time, MBET-3 closes the connection automatically.

Initial parameters programming is essential and includes setting the LAN/WAN-network parameters (IP-address, gateway IP-address, network mask, IP-address of the control server, etc, including setting new MAC-address if MAC-conflict occurs) and remote reading network parameters (baud rate and parity of serial connection, remote reading network number). These parameters must be set first via RS-485/RS-232 port, and after successful connection all the parameters can be set remotely by the server, if needed.

All the connectors of MBЕТ-3 are on industrial terminal blocks except LAN connector, which is standard RJ-45 plug. Mounting should be made by qualified technicians and is on standard M-35 DIN-rail.