Summary
Here is the final summary (from me) of where things stand with the new front-end systems. With Anchal and Ian's recent scripted loopback testing [16224], all the testing that can be performed in isolation with the hardware on hand has been completed. We currently have no indication of any problem with the new hardware. However, the high-frequency signal integrity and noise testing remains to be done.
I detail those tests and link some DTT templates for performing them below. We have not yet received the Myricom 10G network card being sent from LHO, which is required to complete the standalone DAQ network. Thus we do not have a working NDS server in the test stand, so cannot yet run any of the usual CDS tools such as Diaggui. Another option would be to just connect the new front-ends to the 40m Martian/DAQ networks and test them there.
Final Hardware Configuration
Due to the unavailablity of the 18-bit DACs that were expected from the sites, we elected to convert all the new 18-bit AO channels to 16-bit. I was able to locate four unused 16-bit DACs around the 40m [16185], with three of the four found to be working. I was also able to obtain three spare 16-bit DAC adapter boards from Todd Etzel. With the addition of the three working DACs, we ended up with just enough hardware to complete both systems.
The final configuration of each I/O chassis is as follows. The full setup is pictured in Attachment 1.
| |
C1BHD |
C1SUS2 |
| Component |
Qty Installed |
Qty Installed |
| 16-bit ADC |
1 |
2 |
| 16-bit ADC adapter |
1 |
2 |
| 16-bit DAC |
1 |
3 |
| 16-bit DAC adapter |
1 |
3 |
| 16-channel BIO |
1 |
1 |
| 32-channel BO |
0 |
6 |
This hardware provides the following breakdown of channels available to user models:
| |
C1BHD |
C1SUS2 |
| Channel Type |
Channel Count |
Channel Count |
| 16-bit AI* |
31 |
63 |
| 16-bit AO |
16 |
48 |
| BO |
0 |
192 |
*The last channel of the first ADC is reserved for timing diagnostics.
The chassis have been closed up and their permanent signal cabling installed. They do not need to be reopened, unless future testing finds a problem.
RCG Model Configuration
An IOP model has been created for each system reflecting its final hardware configuration. The IOP models are permanent and system-specific. When ready to install the new systems, the IOP models should be copied to the 40m network drive and installed following the RCG-compilation procedure in [15979]. Each system also has one temporary user model which was set up for testing purposes. These user models will be replaced with the actual SUS, OMC, and BHD models when the new systems are installed.
The current RCG models and the action to take with each one are listed below:
| Model Name |
Host |
CPU |
DCUID |
Path (all paths local to chiara clone machine) |
Action |
| c1x06 |
c1bhd |
1 |
23 |
/opt/rtcds/userapps/release/cds/c1/models/c1x06.mdl |
Copy to same location on 40m network drive; compile and install |
| c1x07 |
c1sus2 |
1 |
24 |
/opt/rtcds/userapps/release/cds/c1/models/c1x07.mdl |
Copy to same location on 40m network drive; compile and install |
| c1bhd |
c1bhd |
2 |
25 |
/opt/rtcds/userapps/release/isc/c1/models/c1bhd.mdl |
Do not copy; replace with permanent OMC/BHD model(s) |
| c1su2 |
c1su2 |
2 |
26 |
/opt/rtcds/userapps/release/sus/c1/models/c1su2.mdl |
Do not copy; replace with permanent SUS model(s) |
Each front-end can support up to four user models.
Future Signal-Integrity Testing
Recently, the CDS group has released a well-documented procedure for testing General Standards ADC and DACs: T2000188. They've also automated the tests using a related set of shell scripts (T2000203). Unfortnately I don't believe these scripts will work at the 40m, as they require the latest v4.x RCG.
However, there is an accompanying set of DTT templates that could be very useful for accelerating the testing. They are available from the LIGO SVN (log in with username: "first.last@LIGO.ORG"). I believe these can be used almost directly, with only minor updates to channel names, etc. There are two classes of DTT-templated tests:
- DAC -> ADC loopback transfer functions
- Voltage noise floor PSD measurements of individual cards
The T2000188 document contains images of normal/passing DTT measurements, as well as known abnormalities and failure modes. More sophisticated tests could also be configured, using these templates as a guiding example.
Hardware Reordering
Due to the unexpected change from 18- to 16-bit AO, we are now short on several pieces of hardware:
- 16-bit AI chassis. We originally ordered five of these chassis, and all are obligated as replacements within the existing system. Four of them are now (temporarily) in use in the front-end test stand. Thus four of the new 18-bit AI chassis will need to be retrofitted with 16-bit hardware.
- 16-bit DACs. We currently have exactly enough DACs. I have requested a quote from General Standards for two additional units to have as spares.
- 16-bit DAC adapters. I have asked Todd Etzel for two additional adapter boards to also have as spares. If no more are available, a few more should be fabricated.
|