re combined comments from the rest of the LCLS Controls group:
- It needs to be a requirement that all HVAC values (air pressures,
humidities, temperatures) are available to read in EPICS within 500 ms
of having changed, so that they can be timestamped.
                                                                                
- Note that it would be possible to do the HVAC system with EPICS. The
LCLS Controls Group is available and willing to work with the vendor
to provide training and guidance in this area.
                                                                                
- PLCs need to be standardized to be Allen-Bradley Control Logix PLCs.
We have EPICS drivers for this PLC already, so the job to get the data
into EPICS databases and displayed on screens is straightforward.
                                                                                
- Where there is equipment that runs in its own standalone box, it
may be necessary for EPICS device drivers to be written to be able to
get the data out. LCLS Controls Group could write these drivers.
                                                                                
- It's a concern that the cable trays with sensitive instrument cables
may get interference from the stepper motor cables. Since the high
voltage is already in a separate tray, do we still need one more cable
tray (for a total of 3), so that BPM cables are not in same tray as
stepper motors? This is the what they did at SNS. Mario is not worried
about this and comments: "Stepper motor cables do not run with BPM's in
Injection. A very few BPM's may have short lengths of parallel runs in
the tunnel trays, but that's it. Linac steppers that originate in the
same racks as Inj pass the BPM racks (RF Hut)through to the downstream
penetration. There is next to no interaction between the cable sets."

Here is some follow-up discussion on this point with Dak and Mario:

Stepper motor cables do not run with BPM's in Injection. A very few BPM's may
have short lengths of parallel runs in the tunnel trays, but that's it. Linac
steppers that originate in the same racks as Inj pass the BPM racks (RF
Hut)through to the downstream penetration. There is next to no interaction
between the cable sets.
						Mario Ortega x3612

Do we know the voltage and current rating of the those Stepper motor cables?
And how many there are?.I ask this so we can determine if it is really a
problem and minimize the interference to the sensitive cables.
						Dak Baltazar

The hard part is that we don't know yet which steppers we will be using...
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Comments on "Conventional Facilites Specs for the Sector 20 Alcove" by
Dave Dowell on Aug.2/2004:
- page 2 needs the section for the RF Hut put back in
- tables II-V need, at a minimum, 4 network connections (for the current
plan allowing 4 indendent Gigabit LANs in the injector) at each location
(Laser Bay, Laser Bay Controlled Entry Area, Storage & Local Control,
Load Lock and RF Hut).
                                                                                
- One final concern is that, owing to the very tight tolerances on RF jitter
and timing resolutions (to run at 120 Hz), some shielding may be needed to
reduce the electrical noise in the different locations: Laser Bay,
Laser Bay Controlled Entry Area, Storage & Local Control, Load Lock and
RF Hut. It would probably be easier & cheaper to do this during the initial
construction.

Here is Ron Akre's view of this final concern:
"We have discussed this in the past.  To properly shield the room, all of the
cables going into and out of the room would require proper shielding and
filtering.  If this is not done properly, the cables form a network of antennas
which bring noise into the room and defeat the shielding.  To properly shield
the RF Hut and Laser room would likely cost about 0.5M$.  There is also going
to be crates in the RF HUT and Laser room which I believe will generate RFI.
The decision was made to shield the sensitive devices where they need it.
                                                                                
If we have a better idea of what equipment is going into each room we may want
to revisit this decision."