Controlled Products Systems Group HTG 320-2 ST - Manual (Page 32)

StrongArm Installation and Reference 22
Connecting a Master / Slave Pair
Configuring two operators to be a Master & Slave pair is easy with the Smart Touch Controller. There is
no need to order a special model or any adapters. The area of the board marked Dual Gate employs a
3-wire RS485 serial port for communication between Master & Slave operators.
1. An electrical conduit for the interconnecting wires must span between the two operators.
2. Complete the installation of both of the operators as separate machines and verify that their basic
functions are correct as solo operators before interconnecting them.
3. The two gate operators should be supplied by home runs from separate 20 Ampere circuit
breakers in the main panel, but if there is only one circuit, be absolutely certain that the breaker
and wire size is sufficient for the load of two motors. See the Appendix.
4. External control inputs, vehicle detectors and entrapment protection sensors may be connected
to either gate operator without regard to preference.
5. To interconnect the two operators, route a shielded twisted triple cable wire between the electric
control boxes and connect to the RS485 Dual Gate terminals, in matching order on both
machines: In the RS485 shaded area connect the terminals for Master Com to Slave Com,
Master A to Slave A and the Master B to Slave B using the insulated trio of wires. Connect the
shield to a solid ground at either the Master or the Slave unit (Do not ground both ends). Cut off
the shield and insulate (tape) the exposed strands at the other operator.
6. The Installer Menu in each machine must be set as a Master or a Slave under menu item [dg__].
Set one operator as a Slave [dg_1] and the other as a Master [dg_2]. If the function of any
external input is to be different than the factory default, configure for the desired function on the
operator where that input is connected. Internal functions, such as the close timer or reversal
distance, are controlled by the Master operator regardless of the settings in the Slave.
7. Once set as a Master or a Slave the operators will be in constant communication with each other.
If that communication stops because the wires become severed or one operator is turned off,
both machines will cease functioning and the LCD will display Err4, which is a Master/Slave
communication error. This error cannot be reset until both machines are functional and
communicating properly again.