User's Manual

33
Document Number: 0100SM1401 Issue: 12-16
Embedded MODBUS Gateway
Q data radios have an embedded MODBUS Gateway feature that can be enabled to function like an external MODBUS
gateway. The MODBUS gateway is a protocol converter between MODBUS/TCP and MODBUS RTU protocols. The gateway is
an addition to the Device Server feature on the legacy serial port.
When operating in MODBUS gateway mode, the remote radio provides the same functionality as if there was an external
MODBUS gateway at each remote site of the system. In traditional systems, standalone MODBUS gateways were required to
convert the IP MODBUS TCP protocol to MODBUS RTU, the example below shows a traditional MODBUS TCP system using a
stand-alone MODBUS gateway at each remote site.
When operating in MODBUS gateway mode, the remote radio provides the same functionality as if there was an external
MODBUS gateway at each remote site.
Features of the embedded MODBUS gateway include:
• Support for two independent fully configurable MODBUS gateways.
• Support for two transport protocols: TCP and UDP.
• Support for two modes of TCP operation: Client mode and Server mode.
• User-configurable port numbers.
• Support for up to 16 simultaneous TCP connections (sockets) when operating in server mode.
MODBUS gateway mode provides an easily configurable mechanism for transporting serial traffic over an IP network (LAN/
WAN). A benefit of the MODBUS gateway feature is that the limitation of MODBUS addressing (0-255) can be ignored as
the IP address of the radio can be used giving unlimited addresses to external equipment such as RTUs or PLCs. Below is
an example of a typical system using the MODBUS gateway (remote) feature at each remote site to avoid the limitation of
MODBUS addressing.
Part D – Feature Detail