16
SD Series Technical Manual
MDS 05-4846A01, Rev. H
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. The IP Payload fea-
ture, used at the Master, efficiently passes TCP/UDP payload over the
air, and eliminates the need for an external terminal server. (
COM1
may
also be used for payload data if properly configured via the menu
system. See next example.)
Invisible place holder
Figure 9. IP Polling of Serial Remotes
IP Polling of Two Serial Ports on One Remote
In some cases, it is necessary to poll more than one RTU at a Remote
site. Figure 10 shows an example of such a system. Here, two RTUs are
connected to each Remote transceiver, both using the radio’s serial
ports—
COM1
and
COM2
.
By default, the radio’s
COM1
port is configured for serial management
functions with a connected PC, but it may be configured for data service
using the web interface. This arrangement allows two telemetry net-
works to share a single radio system.
MASTER RADIO
(TCP Server)
HOST COMPUTER
(TCP Client)
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
