[Jenne, Sheila, Terra, Corey]

We've been having trouble with MICH ASC lately.  Sheila suggested that I double-check the TCS power settings, and in fact, the ITMX CO2 guardian is setting the laser to the wrong power. 

At 50W, we want TCS-CO2_X to be at 0.2W, and TCS-CO2_Y to be at 0.0W.  However, the guardian was taking both to 0.0W.  This is because the PSL_power_checker function inside of the TCS guardian has bad gain and offset values (I think).  This function calculates the desired TCS power based on the current PSL power, and the gain and offset values are defined separately for each CO2 laser.  This function wants to set the TCS-CO2_X power to 0.0W, and the TCS-CO2_Y power to -0.2W.  It has a check so that if it's trying to go to a negative power, just go to 0W, which is why both are being set to 0W.  At least for 50W, it seems that if we increase the offset values by 0.2W for each laser, we would be getting the power that we want.  However, I don't know that this will give us the correct CO2 power for any other PSL powers, so I am not changing it.  Someone from the TCS group should look into the calculation of CO2 power versus PSL power in the guardian, please.

After looking into things, I'm actually not sure why we were getting 0.2W for TCS-CO2_X.  It looks like the TCS guardian hasn't changed since its original checkin mid-May, and that it has always been calculating (using the PSL_power_checker function) that it should set TCS-CO2_X to 0.0W in the NOMINAL_LOCKED_CO2_LEVEL state, and that we've been requesting that state in the..... As I was typing, I realized why we weren't getting the wrong TCS powers.  Over the last few months, we've spent a lot of our time commissioining in the Increase_Power state for ISC_LOCK, where we had forgotten to comment out an explicit TCS power request from before we had the guardians.  The TCS guardians weren't requested to do anything until Coil_Drivers, the state after Increase_Power.  So, we were getting the TCS powers we wanted from the explicit request that should have been deleted, and weren't going to the wrong powers because we weren't advancing the ISC guardian. 

When Sheila shuffled a few guardian states over the last few days to make things more clear after we arrive at 50W, she put the TCS request in a state that we are now always going to, so that's why we've recently run into this.  For now, I've commented out the request for the TCS guardians to go to their "nominal" powers, and am leaving in the explicit request in Increase_Power.  Once Team TCS confirms the calculation of CO2 power versus PSL power, we can go back to using the TCS guardians.