One feature we have had customers request is the ability to take a signal from one serial port and split it into many serial ports, to allow serial port mirroring like a simple sort of “Y-cable”. Our classic serial products like the DeviceMaster and RocketPort have used the conventional RS-485 and RS-422 as point-to-point or multidrop, and RS-232 as exclusively point-to-point. The DeviceMaster UP with the Modbus/TCP firmware can however be configured as a “serial splitter” with the ability to send the serial data to up to six TCP connections. No Modbus specific features are used, in operation it acts like a DeviceMaster RTS but with the added ability to perform the serial port mirroring.
The above shows how the data from serial device can be mirrored to six individual host PCs. Communication can be via TCP-based serial application, or via virtual COM ports using our Secure Port Redirector software, available free on request.
If a completely hardware based solution is required we have two configurations that requires no host PCs or virtual COM ports.
By using a DM UP 4 port the data from port 4 in this example is replicated to ports 1-3. The data is sent from port 4 to ports 1-3 internal the DeviceMasters internal TCP connections, no network connection is required at all.
Finally we have an example of a distributed serial splitter which allows the serial port to be mirrored to any location on the network.
By connecting up to six DeviceMaster RTS units at each endpoint to the same network as the DM UP we can convert the socket back to serial, again in a purely hardware based design.
Please note: Using a DM UP as a serial splitter is best used for a serial port mirroring “monitoring only” fashion. Any attempt to write to the one serial port must be controlled by the user or applications to ensure only one socket is writing at any one time. There will be no control over which socket is writing at any one time which could lead to the data streams being improperly mixed.
