PART 1
MASTER/SLAVE OPERATION
A. WHAT IS MASTER/SLAVE OPERATION?
The easy way to understand master/slave operation is by the computer terms “smart” and “dumb”.
•“Smart” machines are controlled by a computer or dedicated microprocessor, such as microwave ovens and
•“Dumb” machines are controlled by simple electronic or physical mechanisms, like
When your installation requires using two gates together, they can be controlled either by the “dumb” method of wiring them in parallel and using limit cams and reclose timers for control (see the Installation and Operation manual for the individual gate operator), or the “smart” method of enabling the Master/Slave programming built into the gate operators.
LiftMaster gate operators are capable of handling any gate combination you’re likely to need, and we strongly recommend using the “smart” method for the following reasons:
1.Synchronization: Gate actions (opening, closing, etc.) are synchronized in Master/Slave operation.
2.Added safety: A fault in one unit affects both units, providing added safety to the system.
3.Reduced wiring: Inputs (radio, exit loops, etc.) need be wired to only one unit in some Master/Slave configurations.
4.Simplified gate setting: Gate controls
Let’s take a quick look at some Master/Slave gate configurations, cover the wiring and setup procedures, then go into the details of each type to help plan your installation.
B. MASTER/SLAVE GATE CONFIGURATIONS
LiftMaster models SL
Figure 1. Master/Slave Gate Configurations.
•In the Master/Slave configuration, one Master unit controls one Slave unit.
•Master and Slave units communicate at 9600 baud via a
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