Ip-To-Serial Application Example - GE MDS iNET 900 Reference Manual

Establishing a
Connection
72
ing may range from 22 to 44 ms, but the radio will not create any
gaps in the output data stream. This mode of operation is
required for protocols such as MODBUS™ that do not allow
gaps in their data transmission. [
•
Seamless Inter-Frame Delay
the end of a message (inter-character time-out). MODBUS
defines a "3.5-character" parameter. [
NOTE: With MODBUS/RTU mode, poll requests may be fragmented
when using COM port baud rates above 19200 bps via a
USB/Serial adapter (FTDI). This may cause incorrect
checksum/CRC errors and thus, timeouts.
•
Custom Data Buffer Size
mum amount of characters, that the Remote end will buffer
locally before starting to transmit data through the serial port.
[
16, 32, 64, 128, 256; 32
•
Commit Changes and Exit Wizard
on this screen (Shown only after changes have been entered.)
A PPP session shows the following possible states:
•
Sending LCP Requests
ents that need to connect.
•
Link Established
ated and an IP address is assigned.
•
Port not Enabled

2.6.6 IP-to-Serial Application Example

You have a choice to use UDP or TCP to establish communications.
This will depend on the type of device you are communicating with at
the other end of the IP network. In this example we will use TCP to illus-
trate its use.
In TCP mode, the transceiver remains in a passive mode offering a
socket for connection. Once a request is received, data received at the
serial port will be sent out through the IP socket and vice versa, until the
connection is closed, or the link is interrupted. In this mode, the trans-
ceiver behaves the same, whether it is an Access Point or a Remote.
(See Figure 2-37 and Table 2-1)
NOTE: The TCP session has a timeout of 10 minutes (600 seconds). If
inactive for that time, it will be closed. The transceiver will
offer the port again for connection after this time expires.
From the PC, establish a TCP connection to the IP address of the
Remote transceiver and to the IP port as configured above (30010—
COM1, 30011—COM2). A Telnet client application can be used to
establish this connection. Data can now be sent between the PC and the
RTU or other connected device.
iNET Series Reference Manual
Seamless, Custom; Seamless
— Number of characters that represent
(Custom Packet Mode only)—Maxi-
]
—Save and execute changes made
—The PPP server is querying for any cli-
—A successful PPP connection has been negoti-
—The serial port is disabled.
]
]
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