Theory of operation – Daktronics Pro Series Operations and Maintenance Manual User Manual

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Each Vortek hoist is connected to the main high voltage power buss through a safety twist-locking plug. This plug

brings in the main 3-phase power that is connected to the motor drive and motor brake located in each hoist

assembly. Also connected to each Vortek hoist assembly through safety locking connectors are 24 V DC power,

E-Stop circuit, and a computer network cable.
The motor drive controls all movements of the hoist. Each drive on each hoist contains programming to identify

it to the network. This programming also includes but is not limited to maximum speed, acceleration, gear ratios

and soft limits. Each motor drive monitors an incremental encoder, limit switches, i-Batten™ safety feature and

emergency stop status. The incremental encoder is used for position control. The limit switches are used for

maximum up and down travel. i-Batten safety feature is used for the detection of both an underload or overload

condition. The emergency stop status is used to detect the operation of the emergency stop system.
Monitoring of each hoist is done over the network using a master drive. The master drive is located in the master

drive cabinet typically at stage level. Included in the master drive cabinet are the master drive and the network

hubs. A 24 V DC power supply that powers the network hubs and the E-Stop circuit is also located in the master

drive cabinet.
The main Daktronics Pro Series controller (VAC) is comprised of a Pentium

class computer, touch screen, keyboard,

joysticks and E-Stop button. The VAC computer runs a proprietary Windows

based application that allows the

operator to perform manual and programmable functions to any or all of the hoists connected to the system. The

VAC is connected to the master drive and motor drives through an ArcNet™ based network operating at 2.5

Mbaud. During operation of the VAC, data is transmitted from the VAC computer through the network system to the

master drive and distributed to the appropriate hoist drive. Likewise, data is received from each hoist drive through

the master drive and to the VAC computer for display by the VAC operating software. The 24-volt dc E-Stop circuit

is also connected to the E-Stop button located on the front of the VAC.

THEORY OF OPERATION