Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G - Manual (Page 16)

<4. GETTING STARTED>
4-3
IM 11M12D01-61E
• Cable:
This is used to interconnect the Fieldbus devices. Refer to the Fieldbus Overview TI 38K03A01-
01E for a description. In a test setup, a total length of 2-3m is sufficient, and we can use simple
cabling (wire with crosssectional area of at least 0.9mm 2 , run as twisted pair with twist interval of
not more than 5 cm (2 inches)). The termination will need to match the connected devices. For
the AV550G use wire lugs for M3.5 (3.5 mm) screw terminals. Some devices may require special
connectors.
Yokogawa can provide information as to recommended suppliers.
Connect the devices as illustrated in Fig. 4.1.
Terminators should be used on both ends of the “trunk”, and any spur runs off the trunk should be as
short as possible. Observe correct terminal polarity.
Fig. 4.1 Connecting the devices
Before using a Fieldbus configuration tool other than the existing host, confirm it does not affect
the loop functionality in which all devices are already installed in operation. Disconnect the relevant
control loop from the bus if necessary.
Do not connect a second Fieldbus master, such as a PC with software for remote setting of Fieldbus
device parameters, to an existing DCSattached Fieldbus system. This may confuse the DCS and
cause it to diagnose a communications failure. Any test setup should be off line.
4.2 Host Setting
For Fieldbus to operate, you need to set the following parameters in the AV550G host. Take particular
care to assign a valid bus address to the AV550G.
Do not turn off the AV550G power immediately after finishing parameter setting.
To enhance reliability, two copies of the parameter settings are written to EEPROM. If you do not allow
at least 60 seconds for this data to be written before turning off the power then there is the possibility
that the old parameter values will be retained unchanged.
AV550G
Fieldbus power
supply
Terminator
Terminator
HOST
F0402.ai
– +
IMPORTANT
IMPORTANT