RuggedCom RX1000, RX1100 manual Serial Protocols Main Menu, Use of Turnaround Delays

RuggedRouter™ User Guide

If configured to packetize on a timeout, the server will wait for a configurable time after receiving a character before packetizing and forwarding. If another character arrives during the waiting interval, the timer is restarted. This method allows characters transmitted as part of an entire message to be forwarded to network in a single packet, when the timer expires after receiving the very last character of the message. This is usually the only packetizer selected when supporting ModBus communications.

Finally, the server will always packetize and forward on a full packet, i.e. when the number of characters fills its communications buffer (1024 bytes).

Use of Turnaround Delays

Some RTU protocols (such as ModBus) use the concept of a turnaround delay. When the host sends a message (such as a broadcast) that does not invoke an RTU response, it waits a turnaround delay time. This delay ensures that the RTU has time to process the broadcast message before it has to receive the next poll.

When polling is performed, network delays may cause the broadcast and next poll to arrive at the remote server at the same time. Configuring a turnaround delay will enforce a minimum separation time between each message sent out the port. Note that turnaround delays do not need to be configured at the host computer side and may be disabled there.

Serial Protocols Main Menu

Figure 158: Serial Protocols Server Main Menu

Note that the Serial Protocols server is disabled by default and may be enabled via the System folder, Bootup And Shutdown menu.

The Assign Protocols menu assigns a serial protocol to one of your serial ports. The Port Settings menu configures the serial port and its electrical protocol.

If any of your serial ports are configured as RawSocket protocol, this menu will configure them.

The Serial Protocols Statistics menu will show you the status and statistics for any established sessions.

The Line Trace menu will provide a line activity trace for the serial ports.

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