Description and Location¶
The LWDAQ driver is, in effect, the network hub for the BCAMs. Each BCAM physically plugs into the driver; these eight ports on the front of the driver are not--despite appearances--ethernet ports, so do plug your laptop into them. The driver has a single ethernet port on its rear connecting it to the network. The LWDAQ driver also has a power supply which plugs into the back of the unit. The driver supplies power to each BCAM over their cables. The driver is located in the Cassegrain cage, on a rack at approximately 7 or 8 o'clock as you enter the Cassegrain cage (with twelve being straight ahead as you enter).
Pictures of the driver can be found here: http://alignment.hep.brandeis.edu/Electronics/LWDAQ/Manual.html
The LWDAQ driver is solid state with no "delicate" circuitry; cycling power is fine. There is no power button: if the device is plugged in, then it is on; to turn it off, unplug it. It HAS a reset button on the front panel, at the end of a row of LEDs. Press and release for a warm reset (software reboot). For a cold reset, the power cord can be unplugged and then plugged back in. The driver will automatically re-connect to the network and to the BCAMs in the event of a power cycle / reset.
The network cable (on the rear of the LWDAQ driver) can be unplugged / re-plugged in if necessary. The LWDAQ driver will auto-negotiate its IP address, but it may require the BCAM module to be restarted in SISPI to restore a network connection with SISPI (see "Software" section below).
The BCAM receive power from the LWDAQ driver. Cycling the power on the driver will cycle the power to the BCAMs. Again, this is fine to do. However, the BCAMs themselves are very simple, low-level devices and are probably not the proximate cause for any communication issue.
Each BCAM is connected to the LWDAQ driver by a CAT-5 cable. If there are concerns about a good connection, a cable can be unplugged / plugged back in.
For this reason, we recommend only ever unplugging one cable at a time (to reduce confusion and the risk of mixing up cables), and even then only if it seems necessary.
If a connection is lost to the LWDAQ driver (because, for example, the power is cycled on the driver or because its network cable is unplugged), the BCAM module will probably need to be restarted in SISPI. No other intervention is needed.
There are no stand-alone software tools outside of SISPI that could aid in general troubleshooting. If cycling power / restarting SISPI's connection to the BCAMs didn't solve your problem, you need an expert.