Secutron MR-2605, Руководство по установке

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Secur-bus Capacitance
Maximum wire capacitance for proper operation of the Secur-bus is 90 nF (nanofarad). Typical
wire capacitance for 22 awg quad cable is 20 nF per 1,000 feet. Thus, for 22 awg quad cable,
the maximum wire run distance is ((90/20)× 1,000) =
4,500 feet . Other types of wire have
different capacitance values. Consult the wire manufacturer’s data sheets for typical
capacitance values.
The following devices may be connected to the Secur-bus. All devices are supervised. See the
section 6.3.7 Entering the Reset Programming Mode on page 48 for information on adding
and deleting devices on the Secur-bus.
Table 8 Secur-bus Devices
Note: Shielded wire has a much higher capacitance value and distances are severely reduced.
Devices Description
MR-2605-T External to control panel.
Up to 4 of each device may be connected.
MR-2605-AT
MR-2806 Mounted inside control panel. See diagram in Figure 5 Panel Assembly and Modules
Locations on page 23.
Notes: Do not run the Secur-bus adjacent to sources of high transient noise such as AC wiring,
telephone cable bundles or computer wiring.
If the Secure-bus must go through a high transient area, use shielded cable.
If shielded cable is used, the distances in the chart above are cut in half.