RAD-ISM-900-EN-BD…
5-4
PHOENIX CONTACT
2476_en_I
Additional System Flexibility
1.
Any RAD-ISM-900-EN-BD-BUS radio can be used in applications where a master PLC
communicates wirelessly to distributed PLCs that are attached to remotely mounted
RAD-ISM-900-EN-BD-BUS radios.
2.
I/O communications uses only one of the two serial communication streams allowing
the other stream to be used simultaneously with other devices connected to the unused
serial and Ethernet ports.
5.1.3
I/O System Configuration Overview
To enable communications between the RAD I/O and a Modbus-based master, the
following radio settings need to be configured.
1.
RAD-ISM-900-EN-BD-BUS radio connected to the I/O:
a)
The Modbus address and communications timeout of the RAD-ISM-900-EN-BD-
BUS radio must be set.
b)
The I/O must be assigned to the serial or local communication stream that will be
controlling them.
c)
When the I/O is used as a stand-alone remote I/O station, the radio is typically
configured as a slave.
d)
If the PLC/Modbus master connects to a RAD-ISM-900-EN-BD-BUS radio in order
to use its I/O as an additional, locally mounted I/O, the radio can be configured as
a wireless master. In this case, the radio’s master settings must also be configured
(refer to “Typical I/O Applications” on page 5-3).
2.
Any RAD-ISM-900-EN-BD-BUS radio connected to the PLC /Modbus master:
a)
The serial (RS-232) port or Ethernet port connected to the Modbus master may be
assigned to a serial communication stream.
b)
If the master is a Modbus TCP (Ethernet) device, the Modbus gateway function
must be enabled. This converts the Modbus TCP commands to the Modbus RTU
commands. These commands are used by the RAD-ISM-900-EN-BD-BUS unit to
control the I/O. The communication conversion is one-way. Only Modbus TCP
commands are converted to Modbus RTU commands. A serial Modbus RTU
master cannot use the Modbus gateway function to talk to other Modbus
TCP-based I/O.
c)
The radio must be configured as a master.
NOTE:
For applications where a single master is polling multiple RAD-ISM-900-EN-BD-BUS I/O
stations, all the I/O stations must be set to the same serial communications stream.
RSPSupply - 1-888-532-2706 - www.RSPSupply.com
http://www.RSPSupply.com/p-12970-Phoenix-Contact-2900016-Radio-900-MHz-Ethernet-Radio.aspx
