PART THREE - OPERATION
SECTION 8 - HART OPTION
Accu4™ Low-range Turbidimeter System
Rev. 2-300
74
8.4 MULTI-DROP
Wiring Arrangement
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When the GLI analyzer is set to operate the HART network
in the MULTI-DROP mode, the master(s) is intended to
communicate with up to 15 analyzers.
NOTE:
When analyzers are operated in the MULTI-DROP
mode, the 4-20 mA analog OUTPUT 1 signal of
each analyzer is dedicated only for network use --
not its normal use. (During startup, each analyzer is
assigned a non-zero polling address, causing its
Output 1 to automatically provide a constant 4 mA
signal.) Each analyzer’s analog OUTPUT 2, how-
ever, remains available for normal use.
1.
Make sure the
SINGLE MODE/MULTI-DROP
switch of
each analyzer is set to the
MD
(right) position.
2.
Refer to Figure 3-4 and connect the 4-20 mA analog
Output 1 signal of each analyzer (up to 15) in parallel
on one cable, matching polarity as shown.
3.
Connect an appropriate sized power supply in parallel
with the analog Output 1 signal, matching polarity as
shown.
4.
Connect up to two masters to the 4-20 mA analog Out-
put 1 signal cable.
FIGURE 3-4 HART MULTI-DROP Wiring Arrangement (for multiple analyzer network)