Section 2 Installation
RS485 is a multidrop connection and allows a maximum of 32 devices to be
connected to a computer system. Personal computers are
not
equipped with
RS485 ports as standard. An RS232 to RS485 converter or RS485 interface
board is therefore required to connect an RS485 to a standard PC. Figure 2-4
is an interconnection diagram showing two TMFs linked to a PC, via RS485
and RS485 to RS232 converter. The RS485 bus, a daisy-chain network,
meaning that the wires are connected at the units as in Figure 2-4.
Figure 2-4 RS485 Multidrop Interconnection TMFs and PC
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Protective Earth Connections:
DeviceNet™: The shield of the cable does not directly short to the device
chassis. In order to achieve proper EMC compliance, the device
conductive chassis shall be connected to protective earth (PE). The
connection can be made via the M6-1.0 threaded connection on the flow
body of the meter/controller.
Ethernet/IP™: The shields of the M12 cables do not directly short to the
device chassis, per ODVA guidelines for an “active device.” The shield of the
power cable does directly connect to the device chassis. In order to achieve
proper EMC compliance, it is recommended to connect the device’s
conductive chassis to protective earth (PE). The connection can be made via
the M6-1.0 threaded connection on the flow body of the meter/controller.
