Servos on FireWire: Overview

Utilizing IEEE-1394 (FireWire^®) for industrial servo control delivers performance, ease of use and low cost

Performance.   Ease of Use.  Low Cost.

ORMEC's new ServoWire®  Drive Network uses open standard IEEE-1394 communications to bring a new level of performance to networking servodrives.   All-digital operation and true Plug N Play functionality simplifies drive set-up and eliminates all physical settings (jumpers, potentiometer adjustments, etc.).   Plus, ServoWire®  interface costs are 50% of the traditional +10V analog interface --- and are just one of the factors that contribute to lower total installed costs.

The new ServoWire®  Axis Module plugs into an ORION®  Industrial PC-based controller, and supports up to eight servomotors and drives.  (An ORION® System can support up to 32 axes.)  ORMEC's new line of ServoWire drives easily connect to ORION®  utilizing inexpensive, thin serial cables defined by the IEEE-1394 standard.  ServoWire drives offer output current from 3/6 to 20/40 amps (peak/continuous current), and feature sinusoidal commutation, smart IGBT power blocks and totally software configurable operation.  Drive I/O provides high speed sensors, hardware overtravel switches and programmable limit switch outputs.

The ServoWire® Drive Network provides a high-speed (200 Mbps), real-time, serial communications link between ORION® ServoWire Axis Module and servodrives/motors.  ServoWire replaces the standard plus/minus 10 volts analog servodrive interface with a new all-digital interface. This high response, digital control network supports servos, pacer encoders, high speed sensors, I/O and programmable limit switches --- offering performance, flexibility and ease of use.

ServoWire®  Overview

• Servodrive network communications implemented using open standard IEEE-1394 (FireWire) communications technology.
• Performance: Serial bus operates at 200 Mbps. Servo loop updates based on number of drives on network (2kHz for 8 axes; 4kHz for 4 axes) as well as software features enabled. IEEE-1394 guarantees real-time network determinism and provides extra bandwidth for communication transfers.
• Ease of Use: IEEE-1394 provides true Plug N Play. All motion control & drive parameters are software-driven. No physical settings or off-line computer setup required---simplifying field replacement of drives.
• Low cost: digital interface replaces bulkier traditional drive interface. Dramatically reduced wiring costs provide installation simplicity.

Click here for an index of technical articles on ServoWire.

Quick Overview & Links

ServoWire®  network operates at 200 Mbps. Eight servos update at 2 kHz servo loop update.  Four servos update at 4 kHz. Network supports servos --- plus remote encoders, programmable limit switches, analog inputs, high speed sensor inputs. Click here for more on this topic.

ServoWire replaces standard +10 Volt analog interface with all-digital interface. No more A/D and D/A conversions between the controller and servodrive. Digital communications allow all drive parameters to be defined in software --- not by potentiometers. Click here for more on this topic.

IEEE-1394 defines an elegant standard for "isochronous" data transfers --- guaranteeing network determinism. ServoWire uses isochronous transfers to allocate bandwidth to servos on network to guarantee timely transmission of torque commands, position feedback and high speed I/O status during each loop update.  Click here for more on this topic.

Asynchronous transfers provide way to manage real-time command and status information on network. After servos are updated each cycle, remaining bandwidth is available for asynchronous transfers. User (or application program) can transfer parameters, monitor variables and process errors in real-time. Click here for more on this topic.

True Plug N Play functionality. No offline computer-based set-up required to configure new or replacement servodrives. Click here for more on this topic.

ServoWire dramatically reduces the installed cost and hassles of system wiring. ServoWire eliminates hundreds of electrical signal terminations with simple, plug-together cables. The cable and connector design are part of the IEEE-1394 standard ... and are essential to the high-speed serial bus communications. Click here for more on this topic.

Lower initial purchase price, interface costs and total installed cost. Click here for more on this topic.