Multi-Tech Systems 7500 - Manual (Page 135)

ION 7500 / ION 7600 User’s Guide Internal Modem Connections
Chapter 5 - Features and Applications Page 135
The ModemGate Protocol
The ModemGate feature creates a communications connection between the
telephone network and an RS-485 serial network of devices. When you specify the
protocol for a meter’s COM port as M
ODEMGATE , all data received by the meter’s
internal modem is automatically transferred to the serial network. ModemGate is
available on either COM1 and COM 2, but you cannot use the protocol on both
ports simultaneously.
ModemGate connections do not connect a workstation with ION Enterprise (or
other master device) to the gateway meter’s COM1 or COM 2 port, but rather the
gateway meter’s internal modem port (COM 3).
The example below illustrates how the ION Management Console’s Sites and
Devices windows appear:
Refer to the ION Meter as a ModemGate technical note for complete details on
configuring your meter for ModemGate.
Telephone
Network
Meter with an internal
modem on COM 3.
The serial network is
connected to COM1.
Workstation with
ION Enterprise
and modem
Each device on the RS-485 loop,
including the gateway meter’s internal
modem, must have a unique Unit ID.
All serial devices must operate at the
same baud rate as the gateway meter.
The Modem Site
The ION 7600 with
internal modem
The RS-485 device network
connected to the meter with
the internal modem.
The same RS-485 serial
protocol must be selected
for connections to multiple
devices along the same bus.