LIGO-G9900XX-00-M LIGO II1 Why are we here and what are we trying to accomplish? The existing system of cross connects based on terminal blocks and discrete wiring has served it’s purpose, but has become unwieldy, particularly in light of the EMI retrofit. In many cases, we have blindly(?) applied our new EMI policies and the result has been to place as many as 6 EMI filters in our slow control and monitoring signal paths. This is certainly overkill and probably detrimental.

LIGO-G9900XX-00-M LIGO II2 What do we like about the cross connects? Flexibility- During installation and commissioning activities you can easily reconfigure to support changing needs. Simplicity- There are no active components. It is tough to beat a wire for simplicity. Verification- It is relatively easy to get to signals during debug. Commercially available- The pieces used to put the system together are all readily available from multiple vendors

LIGO-G9900XX-00-M LIGO II3 What don’t we like? Configuration Control- While wires are simple, lots of wires can become a rat’s nest. The documentation must be kept up to date. Operational Problems- Wires can come loose during debug and operations and can be hard to find. Size- They take up a lot of space. Cross talk and interference- The large loop area of many of the signal paths are susceptible to interference. Cost- The current EPICS interface via VME can have a high per channel cost.

LIGO-G9900XX-00-M LIGO II4 How do we keep what we like and get rid of what we don’t? Focus on the real problems- »Size »Unwieldiness »Overkill in EMI upgrade »Intermittency »……. Focus on the good things »Commercially available »Flexible »Simplicity

LIGO-G9900XX-00-M LIGO II5 Block Diagram of One Possible Solution Analog Module or Chassis Cross Connect Board ADC DAC DIO CPU EPICS IOC CHASSIS Channel Access Analog Module or Chassis Cross Connect Board ADC DAC DIO CPU EPICS IOC CHASSIS Channel Access

LIGO-G9900XX-00-M LIGO II6 Features Analog modules or chassis are connected to EPICS IOC Chassis via shielded cable, EMI feedthroughs, etc. Cross connect board is used to connect from modules to control ADCs, DACs, DIO, ala the current cross connects. Commercial ADCs, DACs, DIO and CPUs would be used CPU runs EPICS and connects to existing control network via fiber Ethernet.

LIGO-G9900XX-00-M LIGO II7 What type of CPUs, bus, modules, etc could be used? There are many alternatives available »PC104 »PCI »USB »….

LIGO-G9900XX-00-M LIGO II8 What has already been done within the collaboration? EPICS has been ported to Linux based embedded CPUs and PCs »PC104 »PCI »As far as we know, USB devices have not been done, but development does not appear to hard.

LIGO-G9900XX-00-M LIGO II9 What would one of these solutions look like and cost? As a design example and exercise, the 40M LSC auxiliary controls cross connects was replaced with a PC104 based system. The 40M LSC is very similar to the site LSC systems. The ADC, DAC and DIO functions are done using Aquarela Systems model AQ and AQ A modules. »There is nothing special about these modules. They were only chosen as an example. Final choices would be the result of a more detailed study A CPU was not chosen, but there are many available.

LIGO-G9900XX-00-M LIGO II10 ADC, DAC and DIO for Design Example AQ Analog I/O Module with General Purpose I/O and PWM Analog Input: 14 channel 12 or 16-bit resolution 0 to 5V / 0 to 10V / -5 to 5V / to 10V individually selectable ranges 100 Ksps conversion rate Internal sample buffer for high speed acquisition Analog Output 8 or 16 channel 8 or 12-bit resolution 3 us settling time 5V output range General Purpose I/O and PWM 2 general purpose TTL I/O that can be configured as input, output or PWM output 4 general purpose TTL I/O that can be configured as input output or 10-bit to 5V 20 us analog input AQ A Digital Output 24 Line Buffered Output (3 X 8-bit Ports) 7 to 35V DC Operation 100 to 350mA Depending on Duty Cycle Thermal Overload Shut Down Over-Current Protection LED for Fault Indication Software Fault Indication Software Fault Reset Internal Ground Clamp Diodes

LIGO-G9900XX-00-M LIGO II11 40M LSC Example Due to the modularity of the system it would require only one type of IOC chassis. Each with the same cross connect board and similar EPICS software. The system require 4 of these chassis. Three of the chassis would be more fully utilized, but still have extra channels and one chassis would be lightly utilized. Each chassis would have: »One CPU »Two AQ Analog IO modules »One AQ A Digital IO module »One fiber to e-net converter Each chassis would take up 2U of rack space

LIGO-G9900XX-00-M LIGO II12 40M Example cont’d There is also a requirement for one cross connect chassis to assemble get signals to/from the front end XY220s. This chassis contains only a cross connect board. Schematics for the example are located on Jay’s web page.

LIGO-G9900XX-00-M LIGO II13 40M Example Costs IOC Chassis: »CPU- ~$400 »Analog IO- 2x$ »Digital IO- $99 »Cross connect board- ~$100 »E-net to fiber-$100 »Chassis, cables, emi feedthroughs, misc- ~$1000 »Total chassis cost- $2231 ea. X 4 chassis= $8924 XY220 Chassis- ~$600 Total cost minus cables- ~$9500

LIGO-G9900XX-00-M LIGO II14 40M Example Costs cont’d What does it replace? »Two auxiliary VME crates, CPUs, ADCs, DACs, BIO…. »All cross connect blocks, wires

LIGO-G9900XX-00-M LIGO II15 40 Meter LSC Design Example Alternatives Alternatives to the Aquarela System boards: »Diamond Systems Diamond-MM-32-AT »Diamond Systems Ruby-MM-1612 »Many others The PC104 based solution used in the design example could be replaced with a USB based solution. »The CPU would be a Linux based embedded CPU running EPICS. »IO would be accessed via a local USB inside the chassis. »Example of the USB IO devices that could be used are available from: –FiberByte DAQ , DAQ , DAQ –Measurement Computing Personal Measurement Device Series –Others We could also use an embedded CPU with PCI slots. This solution would be very similar to the EPICS systems we have already developed for the TCS and TNI.

LIGO-G9900XX-00-M LIGO II16 Conclusions There are a wide variety of solutions available. Many solutions involve little custom hardware design beyond our requirements for custom interconnects Many solutions would involve modest amounts of software porting and development, but much of it may already be available. A more detailed study and analysis of our requirements and available technologies could lead to a solution that would meet most if not all of our current and future goals.