Radio Telescope Site Report, System 1 Team, August 17, 2019, by Glenn Davis

Here is a quick site trip report on the work the System 1 team (Phil Gage, Lewis Putnam, Dave Molter and Glenn Davis) completed at the Haswell Site yesterday (8/17/2019):

  1. We installed Version 4.0 of the System 1 software. This version includes a major new capability that supports manual tracking of astronomical objects. I would like to demonstrate this capability at the next Science or Engineering meeting.
  2. Version 4 included a software update to fix the Elevation Axis Bounce Issue (Erroneous Elevation Axis Status) that was identified earlier this summer and has been investigated for several years. The problem was related to the Elevation Axis Integrity Instruments 232M200 I/O module. Due to a board related hardware problem, the I/O board was always reporting bit 2 of the encoder position data as “stuck” on (1) which would create erroneous Elevation encoder data. The fix required both a hardware and software modification. The hardware modification included moving the bit 2 pin to an unused position on the connector to the I/O module (see #3) then provide a software fix that would read data from this new bit position and re-incorporate the bit data back into the Elevation encoder position data – bypassing the bad bit. This hardware/software solution has fixed the problem. The Elevation Axis is now providing the correct encoder positions through it’s range of motion and the “bouncing” has been eliminated.
  3. Dave Molter moved and soldered the “bad” Elevation Axis hardware pin to support the software modification that fixes the Elevation Axis Bounce issue.
  4. Collected Voltage to Rate information for both axis – data below:
Voltage (V) Azimuth Rates (Degs/Sec) Notes
0.00 0.00 Minimum Potentiometer Setting
0.20 0.04
0.39 0.08
0.50 0.11 Normal Potentiometer Setting
0.75 0.17
1.50 0.33
Voltage (V) Elevation Rates (Degs/Sec) Notes
0.05 0.06 Minimum Potentiometer Setting
0.17 0.07
0.35 0.08
0.75 0.11
1.52 0.15 Normal Potentiometer Setting
3.72 0.30
4.24 0.34
5.00 0.42

Please note: We were unable to produce zero rates on the elevation axis – even with the potentiometer turn all the way down.

Additionally, though we believe we returned the potentiometers back to their normal positions, whoever returns to the site for the next data collection, please ensure the potentiometers are at their normal positions before use.

Glenn Davis