System Wiring - Siemens SITRANS F series Operating Instructions Manual

Figure 5-6 Multidrop configuration in hazardous area
NOTICE
Flameproof conduit seals
Two flameproof conduit seals are required for each device in hazardous area installations.
NOTICE
Equipment approved for hazardous areas
Ensure that the equipment is approved for installation in hazardous areas.
5.4.2

System wiring

The device is slave in a 2-wire Modbus RTU RS 485 bus system. Terminal A on the device
must be connected to terminal A on the master/host system. Terminal B on the device must
be connected to terminal B on the master/host system This corresponds to a half-duplex
communication where the slave will only reply to a request from the master.
This example shows an EMC shielded enclosure for multidrop installation. Cable shield must
be grounded at host system, in connection box, and at flowmeter to comply with EMC
requirements. Keep the cable shield to the ground as short as possible.
SITRANS F Ultrasonic flowmeters FST030 (Modbus)
Operating Instructions, 08/2017, A5E37367739-AC
5.4 Integrating the FST030 with Modbus system
Connecting
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