The Challenge

Diamond Light Source is the UK's national synchrotron, a 3 GeV, 561 m third-generation light source supporting three accelerators and around twenty X-ray beamlines. Each beamline is a motion-control challenge in its own right: a single beamline can carry well over one hundred motors, spanning simple steppers through to servo, piezo and nano motors, driving everything from attenuators and diagnostics to mirrors, double-crystal monochromators, diffractometers and hexapods.

Diamond required more than independent point-to-point moves. Many of these devices; slit assemblies, monochromators, multi-axis stages – require true synchronised motion, where several axes move together along a precisely defined path. Achieving that reliably, at scale, across an entire facility, and through a single consistent software interface, demanded a standardised controller platform rather than a patchwork of one-off solutions.

Our Role

Faraday Motion Controls supplied and standardised the Delta Tau PMAC (Programmable Multi-Axis Controller) platform on which Diamond built its synchronised-motion system. Working across the facility's build phases, we delivered the controller hardware, its integration into Diamond's plant wiring, amplifier crates, encoders and limit-switch interfacing and the standardisation that made a turnkey, facility-wide deployment manageable.

This was not an experimental choice. The Delta Tau PMAC platform already had well over one million axes of motion installed worldwide across applications from general automation and robotics to semiconductor, medical and packaging equipment – a proven foundation on which to build a national-scale science facility.

The scale at Diamond speaks to that reliability: roughly 700 axes of Delta Tau motion control were installed in Phase I, complemented by approximately 800 axes in later phases.

Our Solution

The deployment evolved across two controller generations, each integrated into Diamond's infrastructure:

• Phase I: Turbo PMAC 2 VME Ultralight. A 32-axis controller in a VME crate alongside a VxWorks/EPICS CPU card, linked by fibre optic to two 16-axis UMAC units interfacing limit switches, encoders and external amplifier crates.
• Later phases: Geobrick LV IMS. Following a competitive tender, Diamond adopted Ethernet-based control with the Delta Tau Geobrick Low Voltage Integrated Motion System for the remainder of Phase II and PMAC architecture for Phase III beamlines. The Turbo PMAC in a compact 3U enclosure with an integrated amplifier board, each axis configurable in software as either stepper or servo, plus step-and-direction outputs for pico-motors and high-resolution external amplifiers.

The decisive capability of the PMAC platform is controller-level synchronised motion. Rather than orchestrating coordinated moves in high-level software, where acceleration limits and timing ambiguity constrain performance, the PMAC executes a defined coordinate system on the controller itself, using forward and inverse kinematics to relate real motor axes to the combined motion (for example, deriving slit centre and gap from two independent jaws). Diamond's controls group built their EPICS coordinate-system driver directly on top of this controller capability, so that a combined "slit gap" axis behaves, to the scientist, exactly like any single motor.

That layered architecture only works because the controller platform beneath it is consistent and standardised, which is precisely what Faraday Motion Controls delivered.

The Outcome

The standardised PMAC platform gave Diamond synchronised motion that the facility's own engineers described as highly reliable, delivering true coordinated motion at the controller level across mirrors, slits and other combined systems. Just as importantly, a single common interface now spans every beamline, so operators and visiting scientists work with the same controls regardless of the device.

Perhaps the strongest endorsement is repeat selection: having proven the platform in Phase I and Phase II, Diamond committed to the Delta Tau PMAC architecture again for its Phase III beamlines – a facility choosing the same foundation a third time over.

The approach has also proven transferable well beyond Diamond. The same Delta Tau PMAC platform and its associated EPICS drivers were subsequently adopted by other major facilities – the Australian Synchrotron, for instance, credits the Diamond collaboration and runs the same PMAC and pmac(Coord) driver stack. A controller platform standardised once at Diamond became a reference architecture for the wider synchrotron community.

What This Means for Your Facility

For a synchrotron or large-scale research facility planning or upgrading its motion-control infrastructure, the Diamond programme demonstrates what Faraday Motion Controls delivers end to end:

• The Delta Tau PMAC family, validated across ~1,500 axes and multiple technology generations at a large-scale scientific research facility.
• Full plant integration of controller hardware, amplifier crates, wiring, encoder and limit-switch interfacing, delivered as a coherent system, not loose components.
• Standardisation that scales. Consistent controller configuration and programming conventions that keep a facility-wide deployment maintainable and compatible with EPICS, TANGO and other higher-level control frameworks.
• An architecture Diamond selected across three build phases and that other leading facilities have since adopted as their own reference. A platform that scientific facilities can rely on.

Faraday Motion Controls can take your facility from specification through to a fully integrated, synchronised motion-control system. A turnkey deployment built on the same foundation that powers one of the world's leading synchrotrons.

Consult our PMAC motion control experts to discuss your Beamlines.