> I'm not sure if this is the right forum for this query

this might be the right place, depending.

> I'm having a little bit of trouble with the setup of a Midas system ...
> inherited after the previous guy ...

a rather major problem, but a typical situation.

> There was a point at which it was working.

this is very good. if it worked before, there is good chance it will work again.

> And then there was an unrelated issue in the electrical system which, as a side effect,
> meant that the building lost power for a time, and the entire system had to be rebooted.
> No problem, I thought. I'll just reset and restart all of the software...
> ...and I can't seem to get it to work.

this happens often enough. several things are likely to happen:
- unexpected software updates, i.e. new linux kernel was installed but inactive, waiting for a reboot
- hardware failures, i.e. we usually see blown up power supplies. check that all VME crate voltages are okey. (ask me how).
- firmware corruption, i.e. we have seen VME modules lose their firmware after power outage, had to be reloaded by jtag

> I keep getting the error message "mvme_read_value: Could not perform read!: Bad address".

this is a generic error, it does not mean that software suddenly is trying to read from wrong address.

> I imagine that there is something that needs to be set, twiddled, tweaked, or turned on in the driver. The output of 'lsmod | grep vme' is:
> vmedriver             117742  0

this is not the vme driver we use at TRIUMF, so I am not familiar with it's errors. we use the vme_tsi148 driver and the vme_universe driver. (ask me about them).

> so presumably the driver is at least *present*, even if I have no idea how to twiddle anything on it.

could be the wrong version of the driver or the wrong version of the linux kernel. worth checking log files
to see if kernel and driver version numbers are the same.

> Could anyone perhaps suggest a way forward?

Yes. You will have to tell me much more about your system. You can do this publicly here or privately by email to olchansk@triumf.ca

To start, I need to know your VME setup, what is the crate, what is the VME processor, what OS you run, what VME driver you use, what VME modules you have installed.

K.O.