Honeywell W7750A specifications DIN rail adapters, Lonmark Functional Profile

EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

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M6857

Fig. 8. DIN rail adapters.

The FTT supports polarity insensitive free topology wiring. This frees the system installer from wiring using a specific bus topology. T-tap, star, loop, and mixed wiring topologies are all supported by this architecture. The maximum LONWORKS Bus length when using a combination of T-tap, star, loop, and bus wiring (singly terminated) is 1640 ft. (500m) with the maximum node-to-node length of 1312 ft. (400m). In the event that the total wire length is exceeded, then a Q7740A 2-Way Repeater or a Q7740B 4-Way Repeater can be used to allow the number of devices to be spread out as well as increasing the length of wire over which they communicate. The maximum number of repeaters per segment is one (on either side of the router). A Q7751A,B LONWORKS Bus Router can also be used to effectively double the maximum LONWORKS Bus length. The advantage of using the router is that it segregates traffic to a segment while when using the repeater, all traffic is repeated on each segment. When utilizing a doubly terminated LONWORKS Bus structure, use a continuous daisy-

chain with no stubs or taps from the main backbone, The maximum LONWORKS Bus length is 4593 ft. (1400m) with the maximum node-to-node length of 3773 ft. (1150m).

FTT networks are very flexible and convenient to install and maintain, but it is imperative to carefully plan the network layout and create and maintain accurate documentation. This aids in compliance verification and future expansion of the FTT network. This also keeps unknown or inaccurate wire run lengths, node-to-node (device-to-device) distances, node counts, total wire length, inaccurate repeater/router locations, and misplaced or missing terminations minimized. Refer to LONWORKS Bus Wiring Guidelines form, 74-2865 for complete description of network topology rules.

LONMARK® FUNCTIONAL PROFILE

W7750 Controllers support the LONMARK Functional Profile number 8030 Roof Top Unit Controller, version 1.0

(see Fig. 9).

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