10
SD Series Ref. Manual (Packet & Transparent Mode)
MDS 05-4846A01, Rev. C
IP Polling of Serial Remotes
The transceiver is ideal for use in systems employing a mix of serial and
Ethernet protocols. While many variations are possible, Figure 7 shows
a typical scenario with an Ethernet host at the Master Unit that is polling
serial-based RTUs at the Remote sites.
In this example, the Host Computer is connected directly to the radio’s
Ethernet port, and the RTUs at the Remote sites are connected to the
transceiver via the radio’s
COM2
serial data ports. (
COM1
may also be
used for payload data if properly configured via the menu system. See
next application example.)
Invisible place holder
Figure 7. IP Polling of Serial Remotes
Serial Remotes with Two Serial Ports
In some cases, it may be necessary to poll more than one RTU at a
Remote site. Figure 8 shows an example of this type of system. Here,
two RTUs are connected to each Remote transceiver, by using both of
the radio’s serial ports—
COM1
and
COM2
.
By default, the radio’s
COM1
port is configured for management func-
tions with a connected PC, but it may be configured for data service
using the COM1 Port Settings Menu. (
Main Menu>>Serial Configura-
tion>>COM1 Port Settings
) This arrangement allows two telemetry net-
works to share a single radio system.
MASTER RADIO
(TCP Client)
HOST COMPUTER
(TCP Server)
REMOTE RADIO
(One of several possible sites)
MODBUS® SERIAL RTU
To COM2
Serial Port
To Ethernet Port
REMOTE RADIO
(One of several possible sites)
To COM2
Serial Port
Ethernet Data Port Menu
MODBUS RTU
Protocol
MODBUS® SERIAL RTU