Trane VAV VV550 LonTalk, Руководство по установке и эксплуатации

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VAV-SVP01A-EN 21
VAV Start Up/Check Out Procedure
Note:
Use 105 Ω , 1%, 1/4 W for 22 AWG, Level 4.
Comm5 Link Repeater
A Comm5 link repeater regenerates the signal on a Comm5 link. The configurations on either side
of the repeater should be daisy chain. Both link segments require proper termination (
Figure 5,
p. 22 ).
Link repeater requirements.
A link repeater is required when:
• The total wire length is greater than the maximum wire run length of 4,500 ft (1,400 m).
• More than 60 devices are connected to a link-This total does not include the BCU, the link
repeater, and the temporary use of a service tool on the same link.
• More than eight zone sensor communication stubs (maximum 50 ft) are required on a Comm5
link
Link repeater connections.
The recommended shield connections are shown in Figure 6, p. 22 . Use these connections for
instances where shielded communication wire is used. For an example of using a repeater to create
an extended daisy chain configuration, see
Figure 5, p. 22 .
Follow these guidelines when using a repeater:
• Read the Comm5 repeater installation (3270 3285) information that comes with the link
repeater.
• For information about terminating daisy chain configurations, see "Termination resistance
placement for Comm5 links" on
Figure 4, p. 21 .
• Connect shield-drain wires entering the repeater to a terminal marked with a capacitor symbol.
The entering shield-drain wire must be connected to earth ground at the system panel.
• Connect shield-drain wires leaving the repeater to the repeater terminal marked with an earth
ground symbol.
Figure 4. Daisy chain configuration
Ω
Ω
Termination Resistor