Subject: Re: [sloan-25mlog 2247] 2.5m obslog 20150417 (SJD 57130)
From: Fritz Stauffer
Date: Sat, 18 Apr 2015 17:17:57 -0600
Here=92s a snippet of mcp code that I have on my laptop.  This code is =
old and may not be what is currently running.
This code piece is from the code that processes the move command.  The =
move command is overloaded, and it can have multiple parameters.  The =
move command that is suspect has 3 parameters.=20
The code rejects a move command if the move=92s time is less than the =
current time using a routine to decide when a rollover happens.  Here=92s =
the routine.  It looks like there is a 400 second window that should be =
avoided.
-fs
=
/*=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
**
** Determine the interval between two timestamps, given in seconds since
** midnight UTC ~ 5pm MST.
**
** The routine assumes that within 400s of this roll-over time the =
smaller
** time really belongs to the following day, and acts accordingly
**
=
**=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
*/
double
sdss_delta_time(double t2, double t1)
{
  if(t2 >=3D 0 && t2  86000 && t1 =3D 0 && t1  86000 && t2  =
wrote:
> I am pretty sure the MCP handles this just fine.  Deciding that the =
day changed is far easier than programming the hardware to run the axes. =
I am pretty sure FNAL got this right.
>=20
> I don=92t think it is in the MCP, and it is a red herring to consider =
reprogramming it.
>=20
> On Apr 18, 2015, at 4:10 PM, Russell Owen  wrote:
>=20
>>=20
>> In any case, the axis controllers require =93seconds in the day=94 =
for historical reasons. If anyone ever wants to reprogram the MCP to =
take the full date as MJD seconds then it would be trivial to modify the =
TCC and would eliminate any danger of such things happening.=20
>=20
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