Hach MET ONE 6000P Manuel D'utilisation page 12

Install serial communications
Refer to Figure 7 on page 11 and
instrument with RS485, RS232 or pulse communication.
Network wiring
Up to 32 instruments (12 K load each) can be included in a
RS485 (EIA-485) network with RS485 Modbus or FXB communication.
Use a high-grade wire for serial communications such as Belden 9841.
The manufacturer recommends that the length of the network is not
more than 1200 m (3937 ft).
Figure 8 shows a typical network wiring diagram.
Figure 8 Network wiring
1 Particle counter
2 Particle counter
3 To additional particle counters
4 PC
Connect to the Ethernet
Connect instruments with Ethernet communication to an Ethernet
standard 10Base-T or 100Base-T network. Make sure that the wiring is
applicable for the speed of the network to prevent intermittent problems.
12 English
Table 3 on page 10 to connect an
5 Cable
6 RS232 to RS485 converter
7 Network cable
For this instrument, Ethernet standard 10Base-T is sufficient to transmit
data and is more tolerant of installation errors.
• Length—100 m (328 ft) maximum, single wire length (repeaters can
be used to increase the distance)
• Repeaters—4 (maximum)
• Connector type—RJ45 (standard Ethernet wiring convention T-568B)
Connect the analog output
Connect instruments with the analog output feature to a data acquisition
system. Connect the data acquisition system to the supplied 7-pin
connector, then push the connector in the 7-pin connector on the
instrument. Refer to Figure 6 on page 10 and
wiring information.
Instruments with the analog output feature send a 4–20 mA signal that is
proportional to the number of counts on Channel 1 and Channel 2 in a
given sampling time. The analog outputs are updated at the end of each
sample period. A data acquisition system receives the signal.
Instruments with the analog output feature can have only two channel
sizes.
Use the setup utility software to set the maximum number of counts that
correspond to the 20 mA signal. Refer to
on page 14.
When power is applied, the analog outputs on the two channels (Ch
1 and Ch 2) is 4 mA. When power is removed or there is a sensor failure
or flow failure, the analog output on the two channels (Ch 1 and Ch 2) is
less than 2 mA. Any signal less than 4 mA (zero count value) causes a
negative number in the data acquisition system which identifies that
there is a problem with the signal from the instrument.
Configure the central monitoring software to alarm on any signal less
than 4 mA (zero count value) to get a sensor, flow or power loss alarm
as necessary.
For most 4-20 mA systems, an external loop supply is necessary.
However, this instrument produces the loop power internally. This is true
for both the AC and the DC versions. Make sure that there is a common
reference (ground) between the instrument and the data acquisition
system (pin 4 of the 7-pin connector).
Table 4 on page 11 for
Configure the instrument