The log file is kept on hacksaw at: /home/tom/mmt/celllogs/cell.log
rcell with no options gets and prints a quick status from the cell computer. Among other things it is a good way to find out if the cell computer has been turned on and has booted properly. An example of the output is:
(~/mmt/celllogs) hacksaw $ rcell Status: Running diagnostics Mirror is in TEST mode. boot: 11/17/99 16:06:29 cur: 11/17/99 16:24:32Comparing the boot and current time is a good way to find out if the cell computer experienced an unexpected reboot, such as from a power failure or some such.
rcell -m gets a full snapshot of all the actuator forces, commanded and monitored. A good thing to do is to pipe this output into sort, so that you get the actuators in numerical order.
rcell -m | sort was run on 11-17-99 and gave the following output. This was at 5.29 degrees elevation angle and while we were experiencing a very large anomalous Z moment, so these forces are not entirely typical.
act 1 yellow 13.91 10.78 -0.00 -0.00 act 2 blue -0.74 -3.61 -0.00 -0.00 act 3 red 79.20 76.84 -0.00 -0.00 act 4 orange 87.42 85.91 -0.00 -0.00 act 5 yellow 144.07 142.60 -0.00 -0.00 act 6 blue 139.50 137.42 -0.00 -0.00 act 7 blue 74.21 70.29 -0.00 -0.00 act 8 red 510.60 510.07 -599.55 -603.55 act 9 blue 443.36 440.42 -595.63 -595.12 act 10 red 52.24 48.46 -0.00 -0.00 act 11 yellow -429.38 -433.64 601.52 593.36 act 12 orange -420.82 -424.58 597.59 595.36 act 13 yellow -392.32 -389.72 593.66 587.99 act 14 orange 127.46 123.96 8.29 5.65 act 15 red -18.50 -23.22 -0.00 -0.00 act 16 blue -480.12 -493.15 599.55 602.80 act 17 red -399.12 -402.51 595.63 590.82 act 18 blue -415.71 -417.92 591.70 587.27 act 19 red 94.65 89.00 -0.00 -0.00 act 20 orange -15.92 -21.06 -0.00 -0.00 act 21 yellow -474.64 -473.56 597.59 590.62 act 22 orange 444.66 439.42 -593.66 -597.46 act 23 yellow -207.06 -200.86 347.58 334.62 act 24 orange 106.54 105.36 -0.00 -0.00 act 25 red 19.37 16.30 -0.00 -0.00 act 26 blue 440.83 438.21 -595.63 -593.49 act 27 red 457.19 451.34 -591.70 -594.21 act 28 blue 465.52 459.41 -587.77 -583.63 act 29 yellow 58.66 54.02 -0.00 -0.00 act 30 orange -333.27 -333.79 597.59 592.35 act 31 yellow -398.47 -402.50 593.66 589.45 act 32 orange -414.85 -418.12 589.74 580.43 act 33 yellow -66.41 -75.22 -0.00 -0.00 act 34 red 46.08 45.47 -0.00 -0.00 act 35 blue 519.88 515.21 -599.55 -603.18 act 36 red 439.27 438.33 -595.63 -600.16 act 37 blue 441.98 439.85 -591.70 -593.73 act 38 red -66.10 -75.55 -0.00 -0.00 act 39 orange -376.05 -380.11 601.52 611.39 act 40 yellow -380.87 -383.74 597.59 602.43 act 41 orange -392.46 -385.41 593.66 574.30 act 42 yellow -76.54 -79.74 -12.12 -17.58 act 43 blue -37.37 -42.37 -0.00 -0.00 act 44 red -464.79 -461.49 599.55 587.51 act 45 blue -394.66 -398.47 595.63 578.52 act 46 red -27.46 -31.96 -0.00 -0.00 act 47 yellow -34.77 -35.20 -0.00 -0.00 act 48 orange -96.88 -97.97 -0.00 -0.00 act 49 blue -121.96 -125.54 -0.00 -0.00 act 50 orange -2.95 -5.96 -0.00 -0.00 act 51 blue -4.55 -9.37 -0.00 -0.00 act 52 red -72.18 -74.41 -0.00 -0.00 act 101 yellow 14.48 10.16 -0.00 -0.00 act 102 blue 0.61 0.08 -0.00 -0.00 act 103 red 80.72 78.39 -0.00 -0.00 act 104 orange 88.08 85.65 -0.00 -0.00 act 105 yellow 145.22 143.68 -0.00 -0.00 act 106 blue 141.93 142.30 -0.00 -0.00 act 107 blue 74.40 74.60 -0.00 -0.00 act 108 red 517.71 513.32 -608.72 -631.86 act 109 blue 456.62 458.44 -612.64 -631.47 act 110 red 55.04 53.34 -0.00 -0.00 act 111 yellow -432.68 -435.39 606.75 610.20 act 112 orange -429.40 -429.17 610.68 616.06 act 113 yellow -405.39 -422.60 614.61 617.81 act 114 orange 142.99 146.63 -8.29 -14.90 act 115 red -18.32 -21.65 -0.00 -0.00 act 116 blue -486.17 -487.35 608.72 615.61 act 117 red -410.56 -418.96 612.64 613.10 act 118 blue -431.50 -435.44 616.57 592.07 act 119 red 98.02 96.01 -0.00 -0.00 act 120 orange -16.09 -16.77 -0.00 -0.00 act 121 yellow -484.02 -484.02 610.68 581.51 act 122 orange 459.95 452.41 -614.61 -615.74 act 123 yellow -225.75 -245.12 376.37 395.51 act 124 orange 109.00 110.01 -0.00 -0.00 act 125 red 19.35 16.66 -0.00 -0.00 act 126 blue 453.90 462.85 -612.64 -631.31 act 127 red 476.63 477.59 -616.57 -628.79 act 128 blue 491.08 494.96 -620.50 -633.02 act 129 yellow 59.38 65.43 -0.00 -0.00 act 130 orange -340.21 -343.04 610.68 615.44 act 131 yellow -409.99 -408.55 614.61 558.16 act 132 orange -431.92 -430.81 618.53 617.39 act 133 yellow -63.19 -57.39 -0.00 -0.00 act 134 red 46.38 52.03 -0.00 -0.00 act 135 blue 528.12 533.37 -608.72 -597.93 act 136 red 454.33 476.01 -612.64 -614.86 act 137 blue 462.74 482.68 -616.57 -607.78 act 138 red -63.10 -57.75 -0.00 -0.00 act 139 orange -379.49 -372.11 606.75 627.38 act 140 yellow -388.99 -393.25 610.68 630.84 act 141 orange 0.00 5.11 0.00 5.77 act 142 yellow -91.98 -88.78 12.12 22.42 act 143 blue -37.41 -36.33 -0.00 -0.00 act 144 red -471.05 -475.71 608.72 620.43 act 145 blue -405.80 -404.64 612.64 625.30 act 146 red -26.46 -20.66 -0.00 -0.00 act 147 yellow -34.50 -29.24 -0.00 -0.00 act 148 orange -96.01 -90.39 -0.00 -0.00 act 149 blue -120.98 -115.71 -0.00 -0.00 act 150 orange -2.68 2.67 -0.00 -0.00 act 151 blue -3.45 2.99 -0.00 -0.00 act 152 red -70.95 -65.78 -0.00 -0.00
The bump test is performed (or should be -- better be) every time the support system is turned on and before the mirror is lifted. It is quite important as it can detect severe problems that can endanger the mirror that can be detected in no other way. Specifically, a situation where a force monitor is broken (for example always reading zero), while an actuator is generating an out of control force will be detected by the bump test. In particular, the fact that the force monitor is not working will be detected, and the system should not be run with a faulty force monitor, since we will be unable to detect and respond to more serious problems. In most cases however, the bump test detects more mundane problems.
What the bump test does is to go through all the actuators in the support system one by one and verify that they will both push and pull a nominal amount. At this time the nominal amount is 50 pounds of force.
Each component of an actuator is tested as follows:
The desired force is commanded. Wait 1 second. If the monitor shows force within 10.0 pounds, accept +OK. Wait 1 second. If the monitor shows force within 10.0 pounds, accept OK. If the monitor shows force within 16.0 pounds, accept ? OK. Wait 1 second. If the monitor shows force within 10.0 pounds, accept OK (slow). If the monitor shows force within 16.0 pounds, accept ? OK (slow). Otherwise the actuator fails the bump test.
The above procedure is performed first pushing (positive force), then pulling (negative force). Each axis of a dual actuator is tested independently. They are not tested in X and Y, but rather each "cylinder" and load cell is tested as a unit. System panic checks are performed independently of the bump test and are active while the bump test is running. These tests are described elsewhere.
The axial cylinder/load-cell is called the Main component, and the inclined assembly is called the Aux component. This is true for dual actuators, single actuators have no Aux component.
First off and above all to protect the mirror, in fact this is the only reason the support system panics. Many things can cause a panic. The most common and important are erroneous forces generated by a single support actuator. At all times when the air is on in the system, the system diagnostics are running (they run twice a second). They cannot actually run significantly faster because the force monitors pass thru multiplexors which have settling times which pace how fast we can read out a full set of force monitor values.
The word "panic" has become a catch-all term for any sort of problem with any system involving a computer. What we specifically mean here by a support system panic is that the supply air valves are closed by the computer resulting in a very rapid setdown of the mirror onto the static supports. This happens in the span of just a few seconds and the rate is determined by the orifice size in the supply air valve assembly. We do not want to do this unless it is really necessary, but it is always viewed as a valid option in situations where the software (or operator), is not happy with continuing to support the mirror.
Each actuator is expected to produce a force within some band around what it is commanded to produce. If it does not, we feel that the actuator is out of control and we call for a panic. The exact limits are as follows:
Panic with air off - 88.0 pounds. Warning messages in log file - 22.0 pounds. Panic during bump test - 110.0 pounds. Panic during air on - 155.0 pounds. Panic at all other times - 100.0 pounds.
These all deserve some explanation.
A panic with the air off is a bit of a misnomer, but it means that if an actuator shows a force significantly different than zero, we are unwilling to even consider turning the air on.
We issue warning messages for actuators that are out of tolerance more than we expect any well behaved actuator to be, expecting that these may be in need of attention even though they are not yet causing panics.
We need to open up the tolerance during the bump test since we are jumping the commanded force by 50 pounds and it doesn't respond right away (and we may compare its old response with its new command while it is busy slewing to a new value and panic needlessly).
The alarmingly large value during air on is allowed only for a brief period just after the air valves are opened. In part at least this allows for the -75 pound nominal integrator bias to be active for the initial turnon period. The actuators do produce significant transient forces when air is first enabled and this is necessary to get us up and running.
The value at "all other times" is also larger than anyone would like. Over time this has crept up to almost the bump test value, and I would like to narrow it to something on the order of 40 pounds or so, if our actuators would only cooperate.