Date: Thu, 3 Dec 2020 08:23:38 -0700
Subject: Re: [sloan-25mlog 5252] 2.5m obslog 20201202 (SJD 59186)
From: "Daniel Oravetz"
>                        APACHE POINT OBSERVATORY SDSS 2.5M
>
>                                  OBSERVING LOG
>                           Wednesday December 02, 2020
>
>                                   (SJD 59186)
> (5) At the end of the night we noticed the MCP/TPM GUI is reporting 449
> for
>     three of the counterweights and 222 for the fourth. We confirmed at
> the
>     telescope that the counterweights are indeed all ~450. It appears the
>     MCP/TPM GUI is displaying a false value.
We have seen that happen once or twice over the last month or so, too. To
clarify, the new GUI displays counterweight values that it gets from a PLC
read. If the TPM is displaying a "false value" for one of the four
counterweights, then that seems to point toward an intermittent problem
with what the PLC is reading and providing; i.e., the GUI itself is just
displaying what it's being told from the PLC.
The bigger problem with this is that we can't confidently implement
counterweight controls from the GUI because the cwservo task uses those
PLC-read counterweight values - if they're not all correct, the servo-ing
won't be good.