Endress+Hauser silometer FMC 671 Z, Руководство по эксплуатации, Страница: 16 / 68

Rackbus For system use, wire the Rackbus as shown in Fig. 2.5.
•
For ZA 672 - Computer/PLC wiring see Operating Instructions BA 054F/00/en.
•
Be sure that the system is properly grounded! A difference in ground potential
between the Modbus device/personal computer serial connectors and the
ZA 672 Modbus Gateway can cause damage to the equipment or loss of
module programs.
Analogue and
relay outputs The negative pole of the 24 V DC supply voltage is connected to the negativ terminal of
the analog signals (e.g. 4/4...20 mA) and the circuit zero of the FMC 671 Z/676 Z.
•
Any number of measurement and control units can be connected in parallel to
the voltage output, provided that all potentials are related to negative terminal
of the 24 V supply (R
L
≥
10 kOhm).
•
Only one non-floating device can be connected to each of the current
outputs.
•
There is no limit to the number of floating devices, apart from that imposed by
considerations of maximum or minimum load, see Section 2.6.
Alarms and limit switch relays can be connected as shown in Fig. 2.6.
•
Max. current per wire 2.5 A: for switching capacity see Section 2.6.
BA063E13
Max. 64
Commutec
transmitters
in parallel on
Rackbus
Commutec transmitters FMB, FMC, FMU, PMX, TMT etc.
Fig. 2.5:
Rackbus wiring diagram
Max. current per wire 2.5 A
BA063E12
Fig. 2.6:
Suggestions for wiring together
relays and alarms
Recommended
Alternative 1
Alternative 2
Silometer FMC 671 Z/676 Z Chapter 2: Installation
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