GAM Controller Serial Cable Diagnostics

Time:

202306301300-1515

People:

Erik and Nathan

Spaces:

PHYS 401, Dome

Goals:

1. Inspect the GAM controller serial cable.

2. Reset COM2 port in Device Manager.

Log:

1. Inspecting Serial Port on Control Computer End

   1. The serial port on the back of the computer was found to be a DB9 connecter instead of the DB25 described in the schematics.

   2. The cable seems to be in good condition and the solder connections to the DB9 connector are good.

2. Resetting COM2 Port in Device Manager

   1. To reset, we disabled the COM2 driver in Device Manager.

   2. We opened up DFMTCS and confirmed that COM2 is used to communicate with the GAM Controller.

   3. We then reenabled the COM2 driver and found no change in getting the GAM to do what we want like last time.

3. Inspecting Serial Port on the GAM Controller

   1. According the schematics, there are two serial ports (RJ11) on the back of the GAM controller labelled 'J4' and 'J5'.

      1. Only J4 was connected. This could be the reason why there's a DB9 connector instead of the expected DB25 connector on the back of the Control Computer.

      2. Why is J5 not connected?

      3. Is J5 responsible for controlling the translating stage?

      4. We also found that there's was a plastic blank-off plate near the COM2 port on the back of the Control Computer and another port that wasn't connected to anything.

   2. From this link: https://instrumentic.info/en/rj11-rs232.html#gsc.tab=0, we found that a serial cable that uses a DB25 connector on one end has two RJ11 connectors on the other end.

      1. This could mean that J5 was connected at one point before the Control Computer was upgraded in 2011.

      2. The next step to take is to look into the upgrade logs of the Control Computer to see what changes were made to the GAM Controller connection and to see why J5 is not connected.