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2 host setting, Host setting -3 – Yokogawa Multi Channel Oxygen Analyzer System ZR22/AV550G User Manual

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<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