SIMREX DataMover ESS, Руководство пользователя

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72 DataMover ESS User’s Guide SIMREX MAN.ESS-01, Rev. F
SIMREX Corporation
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, Custom; Seamless
]
•
Seamless Inter-Frame Delay
— Number of characters that represent
the end of a message (inter-character time-out). MODBUS
defines a “3.5-character” parameter. [
1–65,535; 4
]
•
Custom Data Buffer Size
(Custom Packet Mode only)—Maxi-
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
—Save and execute changes
made on this screen (Shown only after changes have been
entered.)
A PPP session shows the following possible states:
•
Sending LCP Requests
—The PPP server is querying for any cli-
ents that need to connect.
•
Link Established
—A successful PPP connection has been negoti-
ated and an IP address is assigned.
•
Port not Enabled
—The serial port is disabled.
3.6.6 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 3-31 and Table 3-1 )
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.
Establishing a
Connection
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.